Never used. I bought 4 and have finalized my setup and only need 3. $58 including shipping in the continental US. Venmo preferred but can do Paypal as well. You pay any payment service fees.
Overall I'm happy. The one thing they could have done to make them better is make the thread pitch on the knob coarser so they were faster to operate. From a sanitation point of view, its just an silicone tube with integrated gaskets so there's nowhere for nasties to hide.
Yeah I've heard some other people saying they're a bit slow to operate, but that's probably nice for dialing in plate chiller flow or whatnot. I'll take it; I'm sure I can slot it into the build somewhere. PM your info.