Gen II Tactical Bolt Knob is direct replacement for all Surgeon Rifles and Bighorn Arms bolts.
Precision CNC machined from Stainless Steel.
 
Threaded 5/16"-24 t.p.i. Shank diameter matched to Impact Precision, Surgeon Rifles and Bighorn Arms bolts for correct blended fit.

Knobs shipped with matte black chrome sulphide finish.