Carlson's Long Beard Ported Turkey Brwoning Invector DS 12ga .665 Choke Tube is manufactured from 17-4 stainless steel and has been specially designed to produce the best patterns when shooting Winchester's new long beard-tm xr turkey loads. This new ammunition features shot-loktm technology that allows for the tightest patterns and longer downrange reach over any turkey load on the market. Pair this ammunition's capabilities with Carlson's Long Beard TM XR turkey choke and you have a devastating, gobbler-killing combination. This choke tube features a 25 percent longer parallel section thus throwing tighter and denser patterns downrange. Ported to help reduce muzzle jump and reoil Designed to get optimum performance from Winchester Long Beard ammo For use with lead, TSS, Hevi-Shot, Bismuth and Steel shot #4 and smaller Made from Heat treated Stainless Steel