The Sporting Clay style chokes are extended, knurled and notched for use with a choke wrench. They are manufactured from high strength 17-4 PH stainless steel with an extremely smooth interior finish and are the perfect choice for skeet, trap or sporting clays. If your club so requires these chokes can be used with steel shot from cylinder through improved modified constrictions. All chokes are marked on the head with the degree of choke and on the body with the exit diameter. High quality, low maintenance, known constrictions and a reasonable price!