Arisaka Defense Finger Stop, Anodized Finish, Black, Fits M-LOK FS-M The Patent Pending Arisaka Finger Stop was developed as a low profile" minimal control accessory. This version is for M-Lok rail systems. Unlike a hand stop" which most people position at the rear of their support hand" the Finger Stop has a rounded profile which is ergonomically designed to be located between your index and middle fingers. This typically places it further forward on the handguard" which also means it doesn't get in the way when transitioning to kneeling or prone shooting positions" where most people move their support hand towards the rear. Additionally" the Finger Stop functions well as a forward limit to prevent your fingers from slipping off shorter handguards onto a hot barrel or suppressor" and as a barricade rest.