Rifled Choke Tube. Made specifically for big game, target and silhouette shooting! Stainless steel construction with black oxide coating. Precise, twist rifling grooves spin and stabilize slugs for increased accuracy. Rate of twist: 1 in 35" right hand twist with 8 grooves. Extended. Fits standard Mobilchoke Beretta and Benelli shotguns in 12 Gauge ONLY Included choke tube key for easy installation and removal.