The Strike Industries AR-15 Trigger Test Jig is perfect for assembly and testing of any AR-15 trigger prior to installation on your rifle. The AR15 Trigger Jig allows you to clearly see the engagement points with normal spring tension. The design enables you to dry fire the trigger without damaging the jig or parts. This allows you make necessary adjustments while checking functionality. It is also a great training aid for trigger assembly installation. It is an absolute must-have for all AR-15 trigger work. FeaturesTrigger parts are visible in motionTrigger installation training aidDemonstrates trigger functionSafe dry fireVise mountable Hammer bumperAccepts selector switch and grip