The AR-15 front pivot pin connects the upper and lower receivers at the front of the rifle. Shooters press it out to separate the receivers for cleaning or maintenance. It works with standard AR-15 upper and lower receivers, detents, and springs. Builders use it on mil-spec builds and most standard lower parts kits. The pin seats into the lower receiver and holds the upper in alignment during operation. An AR-15 front pivot pin keeps the rifle together and allows fast takedown in the field.