The ACE "Harpy" Sentinel Droid is a powerful combat droid housed within a drone-like chassis. Each droid has a powerful central artificial intelligence, capable of making advanced tactical and combat calculations. Held aloft by powerful repulsors, the droid has a substantial inbuilt armament of four variable velocity mass accelerators, which can fire projectiles at less than lethal or lethal velocity depending on the desired result. In addition, it has two hardpoints for additional weapons. The droid also features a chemical deterrant dispenser, which can spray aersolized or vaporized chemicals designed to subdue organic targets. These droids also feature andvanced sensors and a limited duration cloaking device, which can render them invisible for up to 2 minutes at a time.