Unlike everyone else, the British army just could not make a sleeping bag deal with the Teutonic devil, which is Carinthia. So they did the next best thing and copied the Tropical bag and Defence 4 bag and called it the Modular Sleeping Bag System. This is the liner for the thicker, Medium weight bag.
The bag is almost a direct copy of the Carinthia' sleeping bag liner. Most notable differences are the greener colour and slightly different tie-cord points.
Fits straight up inside the Medium weight, or "Defence 4" sleeping bag of the British army. Of course, by altering the places of the tie cords this can be fitted inside others as well. The tie cords are actually pretty close to match the Carinthia's bags.
Used and washed before discharged from service. Apparently, these are made by FECSA, a Spanish company that also made sleeping bags for the Dutch army at least.
Stephen H.
Matthew E.