Optimal choke tube designed specifically with Remington HEVI·SHOT loads in mind, although it also works well with steel and lead. With a diameter of .675", the 12-gauge choke constriction is an impressive .060" for unprecedented patterning — in a 30" circle at 40 yards it patterned at an unbelievable 95%. The 20-gauge tube has a diameter of .5775" with a constriction of .040." Made of heat-treated stainless steel with a black coating for low reflectivity and knurled for easy installation. A must for all turkey hunters. Now available in both 12- and 20-gauge!