Carlson's Choke Tubes Browning Invector Plus Choke Tube 12 Gauge Delta Waterfowl 2 Pk.. This Shotgun Choke by Carlsons Choke Tubes is designed to throw tighter and denser patterns than conventional choke tubes. Compact and proven the Carlson's Choke Tubes Browning Invector Plus Shotgun Choke Tubes have a 25percent longer parallel section in the choke leading to more consistent patterns. Each choke tube by Carlsons Choke Tubes is knurled on the end to allow for quick and easy removal and has the constriction and size laser marked on the end and body for easy reference. Steel shot may be used through these choke tubes with exceptional results. Do not shoot steel shot larger than BB or any steel load faster than 1550 FPS through the Long Range Choke Tube. Loads that exceed this size and speed should be used with the Mid Range Choke Tube. Specifications for Carlson's Choke Tubes Browning Invector Plus Delta Waterfowl Choke Tube: Manufacturer: Carlson's Choke Tubes Color: Black Fabric/Material: 17-4 Stainless Steel Gauge: 12 Choke Tube System: Browning Invector Plus (+) Choke Type: Mid Range/Long Range Diameter: 0.71 in 0.72 in Gun Make: Browning Quantity: 2 Additional Features: Non-Ported Included Accessories: Choke Wrench Features Delta Waterfowl 12ga 2 PK (MR & LR): Browning Invector Plus Package Contents: Carlson's Choke Tubes Browning Invector Plus Delta Waterfowl Choke Tube wrench Carlson's Choke Tubes 07360: Browning Invector Plus Choke Tube 12 Gauge Delta Waterfowl 2 Pk.