"JEBS High-Voltage Black Nitride Waterfowl Choke Tubes are perfectly designed to easily and effectively handle lead, bismuth, and steel, while also being able to shoot any ammunition featuring a wad that is ""flight-controlled."" While boasting a patented & revolutionary interior-bore design, JEBS manufactures tubes that not only produce shot patterns that are more consistent, but feature a shortened ""shot-stream"" enabling for greater knock-down power for those much-needed long range shots. The black nitride finish provides additional lubrication and protects against corrosion and wear. Trust us, if you shoot a JEBS, you shoot the best. Built to handle lead, bismuth, and steel shot Capable of shooting any load with a flight-controlled wad Produces a shorter shot stream for better knockdown power Black nitride finish provides additional lubrication and protects against corrosion"