Great Variety Pack-This pack contains the most usable and popular sizes of poly bubble mailers #000 4×8 and #0 6×10 and #2 8.5×12 inches for all your shipping needs. WATER RESISTANT POLY BUBBLE ENVELOPES: Water-resistant and tear-proof mailer protects delicate products. This mailer provides outstanding storage and shipping protection against water, snow and dirt. MATERIAL – These poly bubble mailers are made out of polypropylene material, 3/16″ bubble cushioning wraps to help keep objects safe in shipping. They are 100% light weight and ad no cost to your shipping destination.