Mestel Safety SGE 400/3 Full Face Mask Military Gas Mask Respirator, NBC 40mm SGE 400/3 EN 136:98 CL3 The SGE 400/3 Gas Mask has multi-purpose applications and the following are their main characteristics: Soft anallergic silicone face seal with double bellow shape for unparalleled comfort. Polycarbonate, transparent (92% visible light transfer), ballistic visor treated with a special coating resistant to chemical attack. Very wide field of vision Weights 653 grams which suggests it is size small but I don’t know what size it is. I think the size is in the label cause ai also said it’s small. I just don’t See size on package. Inside diameter is 7 1/2″ from top to bottom of the part that fits into face and 5 1/2″ from the part that goes from cheek to cheek. The outer portion is 9 from top to chin.