Carlson's Choke Tubes Browning Invector-Plus Sporting Clay 20 Gauge Choke Tube Cylinder. This Choke Tube Made by Carlson's Choke Tubes's has a parallel section in the choke that is 25percent larger than older model Carlson's Shotgun Chokes. The knurled end on the Browning 20 Gauge Invector Plus Choke Tube for Sporting Clays by Carlson's Choke Tubes allows you to quickly attach and remove your Carlson's Browning Shotgun Choke. Specifications for Carlson's Choke Tubes Browning Invector-Plus Sporting Clay 20 Gauge Choke Tube: Manufacturer: Carlson's Choke Tubes Color: Stainless Fabric/Material: 17-4 Stainless Steel Gauge: 20 Choke Tube System: Browning Invector Plus (+) Gun Make: Browning Quantity: 1 Additional Features: Non-Ported Condition: New Country of Origin: USA Features of Carlson's 20 Gauge Invector-Plus Browning Choke-Tube: Tightens the pattern of your shot Compatible w/ Lead Copperplated Nickel Hevi-Shot Bismuth Tungsten or Steel Shot Knurled end for simple removal and attachment Constriction is etched on the side Package Contents: Carlson's Browning Invector-Plus 20 Gauge Choketube Carlson's Choke Tubes Browning Invector-Plus 20 Gauge Sporting Clay Choke Tube Cylinder 18871