Our NEW Sporting Clays with a BLACK FINISH are made from 17-4 stainless and precision machined to produce a choke tube that patterns better than standard choke tubes. These choke tubes feature a 25% longer parallel section in the choke thus throwing more consistent patterns than conventional choke tubes. Each choke tube is knurled on the end to allow for quick and easy removal or installation. Each choke has the constriction lasered on the end for easy reference. These choke tubes may be used with Lead, Copperplated, Nickle, Hevi-Shot, Bismuth, Tungsten, or Steel shot. Due to the thin wall design of this choke system, steel shot cannot be used in the Modified, IM, Full or EF constrictions. Check out our Extended Super Steel section for tighter constricitons that can be used with Steel shot. These chokes are backed by a lifetime warranty.Specifications:Const.: Improved CylinderDia.: .723