Anti-Walk locking pins replace your AR trigger and hammer pins to ensure pins do not rotate or vibrate loose out of the receiver. This is a popular"" inexpensive and drop-in enhancement for tactical"" hard-use guns and full auto firearms. These pins are compatible with a standard USGI style AR style lower receiver with standard GI trigger pins of .154"" diameter regardless of caliber"" including 7.62/.308 length AR receivers.