The government issue, Patrol Sleeping Bag is a great lightweight all around temperature sleeping bag ranging from 30 to 50 degrees.  The Patrol Bag is part of the Military Modular Sleep System designed to use separately or together covering a soldiers needs.  The Patrol Sleeping Bag is made of a durable rip-stop nylon shell with continuous filament polyester insulation.  By using a mummy shape design your body warmth is kept inside the bag and the box foot shape offers plenty of room while making the bag more efficient at its light weight.  The heavy duty metal YKK twin zippers also open from either end of the bag allowing for ventilation giving you temperature control.  There is a lot of  durability in this all around G.I Patrol sleeping bag making it a great lightweight option.