Strike Industries Locking Block Pin for Timney Alpha Trigger, Glock Gen3 and Gen4, Black, SI-G-LBP-T-G3N4

When using Timney Alpha Triggers in Glocks there is a trigger return spring that the mechanism relies on in order to reset the trigger. Unlike the OEM trigger housing Timney's system relocates the trigger reset action towards the front of the frame rather than in the rear.