The Kreb's Custom Enhanced Safety Selector incorporates an extended shelf that allows the shooter to maintain his/her hand position in a regular firing grip while positively manipulating the selector with the trigger or ring fingers. In addition, a notch is cut into the lever that allows for the bolt to be locked to the rear with the safety engaged. Precision stamped from 1mm 1050 steel and heat treated to 50C Rockwell, these are one-piece units and are 100% US made. Notes: Fits AK Stamped receiver rifles. NOT for Saiga or Underfolders. Will NOT fit Yugoslavian-pattern rifles or pistols. Will not fit the C39V2.