I installed one on my Vepr safety. The installation was easy except for drilling the safety itself. Very tough metal on that little piece. I set the rivets by pounding them flat. After the install, I worked the safety many times and it helped tremendously. I took a very fine file to the inside of the receiver where the safety rides. I also put a slight bend in the safety so it now slides like butter from safe lock to fire lock. The movement is smooth and easy. It still has a very positive click and lock, so the safety was not jeopardized.