Grovtec Us Gt Hammer Extensions - Extension Fits Ruger Blackhawk, H&R Topper, H&R/Nef Handi

Clamp-on steel extension adds a serrated lever to the side of the hammer spur to give your thumb a large, easy-to-find horizontal grasping surface. A must-have if using a low-mounted scope, heavy gloves, or you just want a hammer that's easy to grasp...

Brownells