Hunter Specialties Undertaker High Density 12 Gauge Choke Tubes - Designed and manufactured for top quality performance while shooting high density loads, such as Hevi-Shot, bismuth and tungsten. This product has been field tested for optimum diameter producing super full choke patterns. Features blued finish 3-inch long tube manufactured in 41L42 chrome-moly aircraft quality alloy and heat treated to handle these tough loads It's knurled for easy removal Fits a variety of 2-3/4", 3" and 3-1/2" shotguns