This is the inside of the handle for my bathtub faucet. It's a single handle that goes from cold to hot by turning counter clockwise. The stop collar, red, doesn't appear to adjust like my other faucets. From what I've found, it's a Luxart A711FM fixture.
- I've tried to turn the red collar to no avail.
- I attempted to loosen the copper ring, and as I was worried, water started leaking out (so I tightened it back up).
- I fiddled with the red collar to see if I could pull it out without removing the copper ring, and while it'll shift forward a small amount, it won't come out.
- I cleaned out the catch/aerator at the end of the faucet tip, just to be thorough.