I modeled the 9/40 version to fit my Gen 5 G34, and it should fit the 19, 45, 17, and the equivalent 40 cal models. Based on the feedback I've received it should also work on Gen 3 and 4 9/40 models too.

These are designed to clip into the rear serrations of the slide so they may or may not clip onto an aftermarket slide with different serrations as tightly.

Just install the clip on the bottom rear of the slide like in the picture above and it prevents the connector from moving over and resetting the trigger. This does not give you the tactile trigger break feeling or sound like some other dryfire devices but it does allow you to practice magazine changes.

All my models are free — if you want to support the filament habit, send me a small tip here.