Quick-Release For Fast Takedown Without Tools
Pushbutton-release pin replaces the factory pivot screw and nut at the front of the receiver to enable quick, separation of the SIG 556 upper and lower receivers with finger pressure only. Three, spring-loaded detent balls hold the pin in place and prevent wear or binding in the pivot hole or receiver hole when removed. Black oxide finish matches the receiver; stainless steel internal parts resist corrosion.
Big Book Catalog, Issue:68, Page:192
New Product Supplement, Issue:631, Page:009
SPECS: Steel, black oxide finish.