Carlson's Choke Tubes TSS Turkey 20 Gauge Retay Choke Tube .555 Black. The Federal Premium's Heavyweight TSS Turkey Load has a high pellet count in both 7 and 9 shot along with the ability to carry energy further makes them ideal for 12 and 20 ga. Shells will include the FliteControl Flex wad that gives hunters the ability to shoot any choke tube they prefer. Specifications for Carlson's Choke Tubes TSS Turkey 20 Gauge Retay Choke Tube: Manufacturer: Carlson's Choke Tubes Fabric/Material: 17-4 Stainless Steel Gauge: 20 Choke Tube System: Retay Choke Diameter: 0.555 in Carlson's Choke Tubes 38028 TSS Turkey 20 Gauge Retay 17-4 Stainless Steel Carlson's Choke Tubes 38028: TSS Turkey 20 Gauge Retay Choke Tube .555 Black