Your Upper is held in place by pins in the Lower at the front and the rear; this little fella is for the front and it is the longer of the two pins. It has a "D" shaped cross-section and only goes in the hole one way.
If you are frequently opening or changing your Upper in the field, you might like our Enhanced Pivot & Takedown Pin Sets.
- Made in an ISO 9001:2008 factory
- Blackened steel
- (1) Pivot Pin
- All Mil-Spec lowers
- All Mil-Spec uppers
- All Mil-Spec pivot pin detents
Tools required: Punch to remove
Installation notes: Other stores sell a tool to install this pin but it's not really needed, just use the side of the pin to depress the detent. If you take coffee through an IV you might have to come down temporarily to get the required steady hand.