1. External hammer for extra safety while holstering;
2. Longer, heavier first pull that decreases the chance of an ND while drawing;
3. Shorter grip relative to gun size, which many find to be the biggest impact on AIWB concealability;
4. Externally visible firing pin safety that allows verification that the FPS is in the down position; and
5. If you use an FS model, having the safety on while holstering adds an additional layer to what is already a very safe pistol because the safety completely deactivates the trigger and rolls the firing pin striker out of alignment with the firing pin and hammer.