Patternmaster has learned from their 60 plus years of research and developed a choke tube that delivers more energy on target and more consistent patterns without using constriction. Their patented stud ring stops the wad and allows the shot to exit the tube without the disturbance of the wad, producing extremely consistent and devastating patterns. By stopping the wad for just fractions of a second, the Patternmaster choke tubes shorten the shot string by up to 80% putting more of your pellets on target than ever before. Made from 100% 17-4 stainless steel then heat and cryogenically treated for strength, they are some of the most durable choke tubes available. The ported design reduces recoil and muzzle jump allowing for faster recoveries and better follow up shots.