Called a drop-leg gas-mask bag, this black nylon bag is brand new and measures approx 12" x 6-1/2" with a reinforced back. Tapers to about 9" x 5" at the bottom, with an overhanging top with snap buckles. Back has hook-and-loop fasteners to hang it from your belt plus (2) more to strap around your thigh. Also has a 4" x 5" covered pouch on the side, probably meant for a spare filter. All the straps are removable and there are C-rings and belt loops galore, so it has a plethora of uses, possibly a plethora and a half.