This high-quality o-ring set belongs in every shotgun shooter's range bag! The six graphite-coated performance o-rings are sized to fit various makes and models: 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, and many other shotguns that use a gas o-ring (barrel seal). Two different sizes of 12/16 gauge o-rings (left and right in photo) and one size of 20/28 gauge (center in photo) will keep most 12, 16, 20 and 28 gauge shotguns running. Kit includes two of each pictured size for a total of six. Kit Includes:Two 12 Gauge graphite coated rings (Silver in color) for the Remington 1100 in 12 and 16 gaugeTwo 12 Gauge non-graphite coated rings (Black in color) for Beretta and other shotguns, which use O-rings, in 12 and 16 gaugeTwo 20 Gauge graphite coated rings (Smallest in diameter) for shotguns in 20 and 28 gauge