Empty filter canister for gas masks with standard thread (40 mm) so that it can be perfectly combined with gas masks and gas mask hoses. As the gas masks are only intended as fetish items / play items, these canisters are empty and not suitable for respiratory protection. But apart from the great look, it is easy to imagine that you can reach popper heaven with these canisters. Canister for gas masks / Empty, therefore not suitable for respiratory protection / Fits all standard gas masks and hoses