The Montana X-Treme (MTX) 1-Piece Cleaning Rod features the highest strength spring steel, proprietary coating technology and a thrust bearing low profile handle. The thrust bearing handle design puts the force into the rod not the handle making it less likely that your jag or brush will unscrew from the rod.Color Coated Handles:17 to 20 Caliber - Purple - Rod Diameter: .160"22 to 26 Caliber - Red - Rod Diameter: .199"27 to 50 Caliber - Blue - Rod Diameter: .258"338 to 50 Caliber - Gold - Rod Diameter: .325"FeaturesHighest strength spring steelProprietary coating technologyColor coded handles for different calibers Thrust bearing low profile handle that puts the force into the rod not the handle Jag or brush less likely unscrew from the rod