These choke tubes have been built to put maximum lethal pellets on your bird. It features a ported, knurled forend for easy installation in the field without tools. The porting drops gas pressure at the muzzle, helping ease the wad away from the shot, reduce recoil, and dampen muzzle jump. The choke tubes feature internal axial rings to keep the shot cloud on target. The tubes are forged from aircraft stainless steel for years of carefree use, and finished in matte black for concealment. This Hevi-Choke waterfowl choke tube is mid-range (out to 40 yards), perfect for shooting over decoys or flooded timber.