Review on JW Pet AccuAir Gang Valve - 4-Way: Optimize Your Aquarium's Aeration Control by Kevin King

I bought this with some other things for my fish tank. The first arrived defective, one of the yellow caps wouldn't unscrew at all (which would result in zero pressure) I sent it back and Amazon sent me a replacement straight away (thanks Revain!) However the second broke at the cube connector (clear tips). to drop it like the pipe is holding it there. For the price I'll throw it away and get something better. Petco sells valves that are really well made and have never let me down in the past. I should have stuck with it. Remember you get what you pay for.