Carlson's Choke Tubes Gas O-Ring Assortment Kit. These Gas Ring Shooting Accessories built by Carlson's Choke Tubes are perfect for replacing old O-Rings. The O-Ring Assortment Kit by Carlson's creates an airtight seal that will allow you to efficiently run gas system functions without worry. These Carlson's Shotgun Chokes work with many other shotguns that use a gas o-ring making them some of the most versatile O-Rings available. Specifications for Carlson's Choke Tubes Remington 12 and 20 Gauge O-Ring Assortment Kit: Manufacturer: Carlson's Choke Tubes Finish: Graphite-Coated Gauge: 20 12 Gun Make: Charles Daly TriStar European American Armory (EAA) Franchi Winchester Remington Beretta Application: Shooting Features of Carlson's 12/20 Gauge O-Rings for Remington: Works with Remington Model 1100 11-87 Pro Bore Guns G-3 models Beretta Shotguns Winchester Shotguns Franchi Shotguns Charles Daly Shotguns Tri Star Shotguns EAA Shotguns Package Contents: Carlson's Choke Tubes Remington 12 and 20 Gauge O-Ring Assortment Kit 2-20 Gauge Gas Rings 4-12 Gauge Gas Rings Carlson's Choke Tubes Gas O-Ring Assortment Kit 00066