My original bite valve got pulled off by some brush in a tight single track section at the National Enduro. So I ordered this one. The new one has a switch to close off the valve which is a nice feature.
I purchased this to replace the one lost off of my USWE hydration pack. The on off feature is a waste on this one and should be omitted or at least offer one for less money which doesn't have that option.
I have two hydration packs from USWE. The F3 Pro Hydration Pack, and the A3 Avenger. The bite valve fits both of those hydration packs, but cant confirm if it fits any other brands. I will say that the tube looks the same size on the USWE's as Camel Back and all other hydration packs. I couldn't find any information on USWE tube size.
I used it on a hydration pack I got from Costco and I'm not sure of the exact size but it's a smaller sized tube. I also have a Fly Racing pack but it has a larger water tube which this bite valve does not fit. Hope this helps.