I think its difficult to find, but you can just buy a gas mask...
Military surplus store, Ebay.
Sa Tabunok
Gas mask was created in 1914.
yes, they dont make them special for bongs, their just regular gas masks and the bong stores buy the plastic/alyrilic/glass tube to smoke weed from. gas masks are definatly dirtty as fk and are awesome.
Honestly anywhere, i saw one for sell on amazon, ebay probably has a few, check on some websites that sell stuff and you will probably find a civilian gas mask really quick.
A person wearing a gas mask.
I think it stopped gas getting in the mask...
A gas mask is used to filter out toxic agents in the air.
M65 Gas Mask.
The main part of the gas mask is made out of rubber.
its a mask made for ariabians