Product reviews for Arsenal 4.5" Screw for AK Pistol Grip

in states that require "featureless fins" you sometimes need a longer screw to make up for the extra space taken up where the fin locks in between the grip and the receiver. This screw is long enough to lock in a Romanian bakelite grip, a fin plate, and a sling mount plate with ease.
Note that the screw head is slightly smaller than the hex head that comes with newer grips, and thus fits in vintage/surplus grips better. The screw is also slotted for a flathead screwdriver (or your AK cleaning kit flat tool). I prefer the head head for better torque, but this one locked down nice and tight with no stripping so it's all good.