http://bulletin.accurateshooter.com/2015/08/new-screw-on-knurled-dials-for-leupold-scope-turrets/
The s1 elevation dial I got from a couple years back, I think I got it for 65 bucks? I hope my data isnt dated at this point. I had to call in and do it over the phone, no web support for it.
They come without a zero stop by default but you can request the zero stop version. I didnt know that but I called in after the fact (and these pics) and they sent me zero stop version.
The zero stop version limits it to one revolution but you can get more by not tightening it all the way low on the turret, lift it up a tad and then tighten the locking screws and you can make it act as more of a detent and slip over the top with a bit more rotational pressure, sort of like a mtc turret.
It should work on all the scopes vx2 and newer. You just pop off the little black cap for finger adjustability that comes on the turrets from the factory and you expose the screw slot adjustment underneath.
The vx2 above will work, the vxll below will not. You just pry the little black topper off.
The whole turret assembled.
The turret in its pieces. A base, zerostop ring and cap.
The zero stop ring installed on the base.
This is the non zero stop version of the top cap, the zero stop version has a little ball bearing that goes in the divot, that ball bearing is what interacts with the zero stop ring. By raising it up just a tad before locking it down like I mentioned before the ball bearing will hit the stop letting you know you are back to zero but can still slide over the stop for access to a second revolution. Just have to remember that you skipped over it when you dial it back down.
And installed on my vx3