Z-M Weapons Ar-15/M16 Accu-Wedge
Helps promote better accuracy by making the upper and lower receiver fit tighter. Open upper receiver; drop this long-wearing, rubber wedge into the rear of the lower, behind the push pin. Absolutely no modifications required. Mfg: Z-M Weapons SPECS: High-density, thermo-plastic rubber, 1/2" (12.5mm) long.