Add some style and enhanced ergonomics with the MDT Bolt Knob. Designed to give you better control over your existing bolt, the textured soft polymer sleeve and subtle hourglass shape cradles your finger so it can be easily maneuvered without slipping. Available in 2 versions, clamp-on and threaded, the clamp-on version can be easily installed over your existing bolt knob, so there's no need for gunsmithing or modification. Specifically designed clamshells are made for each of our supported inlets and uses friction pads and 3 screws to keep the bolt knob tight and secure. The threaded version uses a universal 5/16-24 thread with an aluminum core and is designed for bolts that have screw on knobs, or for when you want to make a more permanent adjustment.