The owner of GHOST TRIGGERS (maker of the famous trigger connectors) gave us a tip years ago: This is the trigger bar to use if you do fitted trigger jobs on GLOCK 9/40/357 pistols. It’s also a drop in part to to make your gen 4 9/40/357 trigger less harsh. You can also convert your serrated face G19 to the smooth face of the 17 with this part. Or if you just need a new trigger assy as part of your GLOCK overhaul. Compatible with gen 1-4 subcompact (ex G26), compact (ex G19), and fullsize (ex 17/34). NOT compatible with 10mm or 45 calibers, or GLOCK 42,43, 43X, or 48.