MIL-PRF-131K Cl.1 is a laminated Foil barrier material with polyethylene.  MIL-PRF-131 Class 1 is useful in a variety of applications including wrapping of electronic components, aerospace and military instruments, machinery, and many more.
 
Foil Material:
 
Non-hazardous and capable of protecting parts from moisture and water vapor
 
Protects packaged products through robust construction
 
Meant for long-term storage of moisture-sensitive products
 
Substrate material:
 
Foil is an excellent barrier material with a WVTR of .00005g/100 sq in/24hr
 
Waterproof and water vapor proof
 
Meets or exceeds MIL-PRF-131K Class 1
 
Specifications:
 
36" Wide x 200 Yard long roll
 
Comes packed in a 36"x10"x10" box weighing 50 lbs
 
NOTE:  The MIL-PRF-131K specification has been revised by the military and is now MIL-PRF-131L.  Revisions such as this are common, the material remains the same.