This set of choke tubes from Carlson is designed especially for the waterfowl hunter. Each consists of a long range and a mid range extended choke tube. Each tube has the constriction and size laser marked for easy reference. They are constructed of 17-4 stainless steel and are designed to throw tighter and denser patterns than conventional factory choke tubes. Steel shot may be used, however do not shoot steel larger than BB or any steel load faster than 1500 fps through the Long Range constriction. All loads may be used in the Mid Range tube.Specifications:12 GaugeExtended choke tubeNon-portedLaser marked for easy referenceMid Range ..70525 to 40 Yards17-4 stainless steelMatte Black