Review on Hemper Tech Universal Cleaning Plugs+Caps for Glass Water Pipes/Rigs - Ideal for Cleaning, Storage, and Odor Prevention by Popeye Knight

I've tried these forks in about 10 pieces ranging from standard 14mm holes to STAX 34mm pieces and in between. Only one of my tubes, a small bubbler, has the plugs on both ends staying tight. In all other cases, at least one side of the pipe (and sometimes both) has slippage problems. You certainly can't clog both ends with most glassware and shake the salt + iso inside like crazy. Instead you plug in pegs, place your thumbs awkwardly on the pegs to create extra pressure, and then fail because the pegs are double-ended hollow, and when you use your thumbs for pressure you just land your thumbs inside the hollow plugs. and now you twist it at an angle. I like it about the pipe he's working on. Good idea, I won't buy again. Maybe try a different brand.