I've had some recent turning job where I've had to go back & forth between 2 X positions until proper depth is achieved (an internal grooved section inside a bore). I already had a similar stop which was mounted on left side of apron. I would stop on that & then unwind to the right up to a specific dial setting. Worked fine but I'm inherently lazy & wanted something that would stop on both sides & prevent possibility of brain fart over-cut-oops by over-rotating the dial or losing track of position (which happened). My #1 version clamped secure & worked well so I thought just clone it & make another. But turns out the bar length would not fit some of the lathe features on the right side of the apron, it had to be shortened & some bevels. I also thought it would be nicer to have one of those quick release clamps. Half turn unclamp, slide to position, half turn clamp, no reaching for hex keys to loosen & tighten cap screws. These handles are sprung so you can pull up a bit further & rotate to some other convenient détente position so its out of the way. My first stop had two 8-32 cap screws. I used 2 screws mostly to keep the upper/lower parts aligned so the clamp doesn't want to rotate out of position as it slides along the V. So I thought this version would require a dowel pin > hole or something because the assembly is free to pivot on the 10-24 handle stud. Turns out I got the parts fitting nice, they stay aligned to the bed because the gap is quite small & don't really rotate out of position. So hear it is, hopefully self explanatory. Any questions fire away.