Check the listing for details. PATTERNMASTER CODE BLACK GOOSE CHOKE TUBE FOR 12GA BROWNING INVECTOR DS 5488. Condition: New. Listed at 89.99 USD. PATTERNMASTER BROWNING INVECTOR DS CODE BLACK GOOSE CHOKE TUBE MODEL 5488 12ga Browning Invector DS Goose CODE BLACK Product Description Patternmaster's CODE BLACK GOOSE tubes will extend out the end of your barrel 1 1/2 inches and has an effective range out to 70 yards. The difference between the Patternmaster CODE BLACK DUCK and Patternmaster CODE BLACK GOOSE is the length the tube sticks out the barrel. (DUCK=1" vs. GOOSE=1 ½") The added length is to accommodate a 3 ½" shell and still achieve a Full pattern. You will see a patterns similar to a Full constriction choke on paper with a 2 ¾" 3’ and 3 ½" shell, but because of the patented "stud ring" inside the tube, there is a much shorter shot string. This shorter shot string will allow more shot on target all at once so your down range energy is sure to kill instead of cripple. Pick your favorite shot size to use which can range from 8 to T-Shot Non-Toxic/Steel and Lead 8 to 000 Buck. CODE BLACK GOOSE tubes only come in a Non-Reflective Bronze titanium coating and are ported. Patternmaster tubes are made of Carpenter Custom 630 (aircraft quality) 17-4ph stainless steel and are heat treated to the optimum level for best performance. Note: Testing done by Ballistics Performance has determined that ammunition with velocity of 1550fps and below will achieve the best results with Patternmaster Tubes. Not for use with ammunition containing flight control wad or slug ammunition. AUTHORIZED PATTERNMASTER DEALER