Here is a fabric liner designed for use with the warm weather rectangular sleeping bag, or similar..
 
Velcro closure front opening, and box section toe to give plenty of room if you have to sleep with your boots on!
 
Fully machine washable...
 
Weight is 0.52 kg.
 
Measures approx 170cm long plus a hood, and 85cm wide - when laid flat on the ground...
 
Brand new unissued, recently released through surplus disposal channels, so grab a bargain!!
 
Label reads 'LINER, SLEEPING BAG, ARCTIC'  NSN 8465-99-132-1389