Carlson's Choke Tubes 65015 Carlsons, Beretta Optima HP C455 Choke Tube, Super Steel.708 The beretta optima HP (a-400) Super steel choke tubes have been beefed up with carpenter 455 stainless steel, adding more strength to this choke ammunition By using the new carpenter 455 material we have manufactured a choke that hunters can Now Use with steel, hevi shot, and other tungsten shot shells Choke tubes in modified, improved modified, full, and turkey choke constrictions Made of 17-4 stainless with a knurled extension and a blue finish Mid range extended steel shot choke tube - for those situations where you are Shooting 25 to 40 yards