Acetech AT2000R Tracer unit incorporated in a high quality Predator S silencer for 14mm ccw screw thread. The Acetech Predator S works on a rechargeable 1x AAA battery (included). The tracer unit is suitable for green and red tracer bb's. You can easily charge the tracer unit with the included Micro USB cable. Supports 30 rps. When you don't use the tracer for a while, it switches off automatically to save the battery.