What makes field training with projectiles so effective is the pain that comes with getting hit with one. The StressVest ($2,500 an up) takes the projectiles out of the equation while still delivering the same stressor needed to take a gunfight training seriously. The system ultilizes a laser insert that goes on a real gun and fire an eye-safe laser pulse with each pull of the trigger. When the StressVest takes a hit, depending on your settings, it delivers a vibration or a localized shock to the abs that intensifies with every successful hit.