Vortex Viper PST Shim for CRS Zero Stop: (Pack of 10) – OVT-S-10
Viper PST, HST, and HSLR elevation turrets utilize the CRS (customizable rotational stop) shims to allow you to quickly and easily return to your zero point. CRS Shims are installed after sight-in, and cause the turret to stop after turning slightly past your zero point.