Carlson's Hammer Expander provides easy cocking for left or right hand use. Balanced and lightweight, it is easy to install, and helps prevent uneven wear of trigger and sear surfaces. The knurled body affords positive non-slip cocking, and it may be used with or without telescopic sights. The hammer expander is .375" in diameter and 1.5" in length. Made in USA. This model is compatible with all T/C Contenders and most exposed-hammer firearms (rifles, shotguns, and handguns).