Modular Sleep System Review – Inexpensive Gear You Need to Grab

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Last Updated on December 14, 2020

Everybody loves a good deal and when I see one I try not to pass it up. If I do, I am usually reminded of that great opportunity that I wasted at some point in the near future and have a Homer Simpson “Doh!” moment where I slap my head in disgust. Fortunately for me, I was able to take advantage of what I considered to be an excellent opportunity to get a piece of very high-quality survival gear for a ridiculous price.

I was at a gun show recently and as I was scanning the tables I noticed a vendor with sleeping bags laid out. I noticed that they were the modular sleep system so I went over to take a look. He had one on display opened up and invited me to inspect it further which I did. I knew that these were surplus, but on inspection, it appeared very close to new.

The only signs of wear really were some slight fraying along the edge of one zipper but the bags were in great shape. What sold me was the price and $75 later, I walked out of that gun show with an awesome piece of equipment for huge savings.

For some background, the Modular Sleep System as it is officially called was designed by Tennier Military Products specifically for use by the Military. It is also known as the Extreme Cold Weather sleeping bag.

What is the Modular Sleep System

The Modular Sleep System will keep you very warm when temperatures drop.

The modular sleep system itself consists of 4 pieces counting the sack. The bags all join together giving you a Lego set of sleeping options. You have a green Patrol bag, a black intermediate bag, and a woodland camouflage waterproof bivy sack. Each piece can be used by itself or in conjunction with the other pieces to give you a system that is rated to keep a soldier warm to -20 degrees.

In warmer climates you can use the patrol bag by itself which is rated for use at 30 to 50 degrees Fahrenheit. The Intermediate bag is designed for use in cold climates ranging from -10 to 30 degrees Fahrenheit. Add them all together and you should stay nice and warm at temperatures lower than most of the country normally sees. If you are wearing long johns and a fleece, the modular sleep system is supposed to keep you warm down to -50. I don’t believe I will ever get a chance to test that but if I do, I’ll let you know how it goes.

Why was I looking for a sleeping bag? Actually, I wasn’t, but that is the way the last couple of gun shows have gone for me. I walk in there looking for one thing but end up walking out with another. No matter how many times I pass the tables with the nice Barrett M82 beasts on them I can’t do more than linger. I spend my time going up and down each aisle because from time to time you can find great deals. I wasn’t really looking for any specific firearm although several caught my eye so after making my rounds once I came back for my second pass.

I have Wiggy’s brand sleeping bags that I purchased for my wife and myself. The motivation was camping, but I wanted to have something that would last in other environments and situations too. This is my bag that I always take hunting also and I found Wiggy’s at the recommendation of The bags are well built and very nice but they aren’t small.

The model I have doesn’t have a cover or sack over the bag but it is supposed to be warm down to -20. My feet were a little cold at 26 this past year and that was with long johns and socks so I don’t imagine 40 degrees colder would be any better.

Last year I also went with my son-in-law to the woods for our yearly hunting trip and he had his issue Modular Sleep system and I admit that I was impressed with the options he had. We didn’t have this system back when I was in the service and all I got was a regular bag. No cover or liner went with it and my son-in-law talked about sleeping out in a field in the middle of a rainstorm and staying nice and dry. Plus this equipment was made in America which is more than what the major bag manufacturers can say. Impressive!

All of these thoughts came to me as I was standing at the gun show looking over the Military Sleep System bag that had a lot of great benefits and a super price so I bought it. I don’t believe you can find a better piece of sleeping gear for the price I paid. Brand new these sleep systems cost $499 on the US Calvary website. If you get a comparable bag made from Wiggy’s with a bivy cover it will be about the same cost.

You can find these older systems yourself out on Ebay, but make sure you are getting military surplus and that the bag is manufactured by Tennier. There are knock-offs from China out there which won’t be anywhere near as good and the new models are made with ACU camo pattern. If they have actual photos, you should try to match up the NSN# from the Military.

There are also some Tennier bag components for sale on Amazon.

  • Camo Green Patrol Bag- NSN # 8465-01-398-0685, X-long NSN # 8465-01-452-1688
  • Black Intermediate Bag-NSN # 8465-01-398-0687, X-Long NSN # 8465-01-452-1690
  • Woodland Camouflage Waterproof Bivy Cover-NSN # 8465-01-416-8517, X-Long NSN # 8465-01-452-1695
  • Black Stuff Sack-NSN # 8465-01-398-5428

Good Points and Bad Points

I’ll start with the bad points first. This bag is a beast and the whole setup weighs about 11 pounds. If you are worried about the weight you should consider that. With the weight comes bulk. The sleep system comes with a compression sack, but you aren’t going to be able to roll this up into a nice tiny Chihuahua sized ball and throw it in your cargo pocket.

I can handle the weight if needed, but a smaller frame person won’t. It is also something you have to consider if this is your plan for a bug out bag. Is it possible to carry this bag? Absolutely, and soldiers do it every day but you may want to adjust weight in other areas.

The good points are construction, price and utility. This bag is made of heavy duty rip-stop nylon and Gore-Tex. Anything that the military uses is designed to stand up to abuse so you can rely on these bags by Tennier lasting you for a very long time with normal use and care.  The price is unbeatable and I have even seen some places on Ebay that are cheaper than what I found.

If I could go back to the gun show right now I would buy a few more. These bags can be used in place of a shelter if needed so you don’t even have to have a tent to stay warm and dry. And, they don’t have to be used for camping only. If your power goes out in the winter, this would give you a great way to stay nice and toasty without power or a fire.

So, if you are in the market for a sleeping bag that will keep you warm and cozy in a wide array of environments, is made in America, and will last you a lifetime of use I would look into picking up a surplus Modular Sleep System. You won’t be disappointed.

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Freedom-loving American doing what I can to help prepare and inform others. Editor and creator of The Prepper Journal 2013-2017, 2020 -

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THANK YOU! This is the best article I have read all week. I had no idea that these even existed. I am going to search the net and get one. Once again, many thanks.


Glad we could help! I am sure you will like it once you get one.


got mine and cant wait for a sub zero snooze opportunity.
i see weight estimates from 8 to 13 lbs. i am pretty sure 11 is correct.

Jeremy Ryan Brandon

This article is right on point. After 14 years (and counting) of active duty, this is by far one of the most reliable pieces of gear the Army has issued to me. I recommend a lightweight sleeping bag liner to go along with the system so that you can dial in your perfect comfort level. A liner also keeps you from having to wash the bag as frequently. As far as the weight goes, you will need all the components only rarely, and if you don’t expect extreme temperature swings, you can usually get by with just the bivy and… Read more »

Pat Henry

Thanks for the affirmation and the comments Jeremy!



Just an FYI, the current cost on ebay is about $85 – but 11lbs is just too much


There are good deals on these sleeping bags and while many knock the temperature ratings or bulk and weight they are hard to beat for the price. To get the most out of these in cold weather one must dress accordingly as the temps go down and the military does not want you sleeping in your BVDs at Minus-20 but dressed warm enough to survive for an hour should you need to get out of it fast in an attack.


I am revisiting this article…. Last year when I first read it. I had already been looking to buy 2 cold weather bags for bug out situations. So I did some research on these bags. I found a lot of positive reviews. I even watched videos on YouTube. So I searched eBay. I found a seller(armygear-auctions)who had them in different grades. I picked 2 of his “excellent condition” bags. I paid $79 apiece. I messaged him and asked about reduced shipping. So he created a custom listing for me. Anyways back to the bags. I live in New Hampshire. So… Read more »

Derek Holland

I have two of these that just never made it back after drill…hehe. I’ve slept in 5 degree weather in the back of a Wrangler with them and was snuggly warm, just gotta zip up all the way and rebreathe into the bag. Going on the Ozark Highlands trail this weekend for two nights and it’s going to be about 10 degrees! Weight will slow you down a bit.

Pat Henry

Yes, that is the trade-off I guess. I don’t think I would ever take these with me in a pack but for situations where I didn’t have to haul them around myself they are so good.

Victor Bennett

Hey Pat, thanks for the helpful article! Do you know how much the pieces way separately? I would probably only use the intermediate bag and bivy on most of my trips.

Pat Henry

I don’t know the individual weights and my bag is in the attic with the hunting gear right now, but I have a friend currently on active duty who does the exact same thing as you are planning. The weather dictates that obviously, but for most of the year, he only uses the bivvy and the intermediate too. He did sleep outside one time in the snow with all three and said he was completely comfortable.


Best bag out there tbh. Tried many others, this was meant to be latge enough to fit a soldier with gear on if need be, most bags will have you screaming in claustrophobia and are light, but lack in durability and modularity. This and a 10×10 tarp with 550 cord is all anybody needs to sleep anywhere, anytime. Small mods would be to add a mosquito net flap to the patrol bag, and add another superthin sf bivy from snugpak to essentially make two bag sets for additional contingency. Sleeves also for those who lkke to sleep armed and prefer… Read more »


That 11 pound figure can’t be right. Just the Bivy and the Patrol Bag are lighter than the old OD cover for the M-1949 Mountain Bag, which I loved, alone. As far as bulk, rig the system so that you can carry it, USMC Field Transport style, in a horseshoe around the upper perimeter of your ruck using cinch straps to the MOLLE loops. Use a poncho or the USMC 80″ x 90″ lightweight MARPAT tarp as your outer layer on the roll. The tarp is your shelter also and only adds about 2 Lbs. Easily configurable with 550 cord.

Fed up with laws

Mine weighs 9.5 pounds, I just weighed myself with and without it on a quality scale that does everything including bone mass and all bio metric. The only difference between mine and system above is mine has the rare Grey stuff sack instead of the black one. I don’t like black anything because it’s not a natural camo color in the woods. That’s the whole 4 part system at 9.5 pounds, and that’s a pretty new weight too not worn out, I haven’t used it that much yet. Maybe the 11 pounds is actually with the sleeping pad as well.… Read more »

Randy Davenport

Just found this. I’m disabled and low income. Anybody want to donate a complete to set to me? Pastor dot spaceboy at gmail dot com

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