TandemKross Challenger Bolt Knob Features The TandemKross Challenger Bolt Knob features an enlarged profile and multi faceted design making bolt operation faster and more confident compared to the smaller factory knob it replaces. Textured and extended for easy use the knob gives the shooter more positive purchase even with gloved hands or in adverse weather. Removable O-rings allow the knob to be customized for personal grip preference giving each shooter the ability to dial in the feel that works best for them. The knob is easily hand tightened but also features a socket for a 5/16 inch allen key ensuring it can be mounted securely to the bolt handle. Built to fit the common 5/16x24 thread pitch found on the Ruger American Gen II and all centerfire models of the Ruger Precision Rifle the Challenger also extends compatibility to popular bolt actions from Remington Howa Springfield Tikka Savage Faxon and Aero Precision. An included polymer cosmetic cap can be optionally used to keep out moisture or debris when the allen key socket is not in use. This durable lightweight upgrade is designed to improve bolt manipulation speed without adding unnecessary bulk to the rifle. For Ruger American and other compatible bolt action owners who want a more ergonomic bolt knob the TandemKross Challenger is available for sale at GrabAGun. TANDEMKROSS Challenger Bolt Knob Specifications Manufacturer: TANDEMKROSS Model: Challenger Bolt Knob Color: Black Thread Pattern: 5/16x24 Compatible Hosts: Ruger American Ruger Precision Rifle Remington Howa Tikka Savage Weight: 0.03 oz Available At: GrabAGun