They're actually knockoff pipes from Hong Kong. I got them as a set, however the inflow was way too long. They sold a lot of curved glass pipes there, so I bought one and taped up an intake pipe thing to it. The inflow is slightly smaller than the outflow.. so I actually had to burn the tube a bit and shove the pipe in.
I am unfamiliar with how many gallons this tank is, so if I knew that I may be able to steer you in a direction with dwarf puffers. The problem is when you get 2 males that reach sexual maturity they are VERY aggressive.