These are unused replacement eyelens sets (2 to a package) for the military ABC-M17 and M17A1 field protective masks. If you have one of these gas masks, then here's your chance to get a replacement outserts eyelens set. Or, here's a start to building your own mask, goggles, or whatever. Original cost was $16.94 per set. 3-3/4" wide by 3-1/2". Clear, scratch resistant plastic material surrounded by rubber. Price is for a set of two.