Slapped this replacement valve on my old bottle and it clicks in snug with no leaks. The bite mechanism takes a little getting used to compared to my last mouthpiece, but once you get the hang of it you can drink mid-run without stopping.
Natalie R.★★★★☆
The hands-free valve works exactly like it should on long trail runs, and I can drink without breaking stride. Only gripe is that it takes a bit of firm biting to get flow going at first, but it loosens up after a few uses.
Sebastian N.★★★☆☆
The hands-free drinking works fine once it's on, but the valve started tasting rubbery after a couple weeks of daily use. It does fit my bottle's bite tube without leaking, so it's serviceable—just not the upgrade I was hoping for.