100 10x13 x 2" Expansion Poly Mailers Bags Plastic Shipping By ValueMailers Expansion Poly Mailers ( EXPANDS TO 2" ON BOTTOM) Strong polyolefin mailers protect products from moisture during shipping. Feature gusseted BOTTOM to allow for thicker items such as binders, books and catalogs. Stuff with 20 to 40% more than regular mailers MATT FINISH (Labels adhere easily) 2.5 MIL Mailers are puncture and tear resistant.