The PX-S2000RD shotgun ‘red ring’ sight system, lets you shoot with 100% confidence, meaning you never miss a shot due to misalignment. The ideal sight for vermin, pigeon and Practical Shotgun shooting. Not suitable for side-by-sides. Fits a flat rib from 5.5 - 12.00mm width. For shotguns with a tactical rail, we recommend the purchase of our Weaver/Picatinney base Mount Rail.