Though the appeal of the gas mask bongs may lie partially in their spooky aesthetic, they are valued mostly for the way they force smoke into the lungs. The seal around the user’s face, designed to keep out chemicals during an attack, locks in the marijuana smoke, forcing the smoker to inhale it all at once.

“It’s kind of a step above a bong,” said Rick Cusick, associate publisher of the marijuana-themed magazine High Times. “It makes for a slam dunk kind of thing.”