Compact tracer unit for better shooting experience in dark rooms or night games Supported Glow-In-The-Dark Tracer BBs Built-in high power UV LED technology illuminators Very sensitive motion sensor Rechargeable lithium battery charged by mini USB cable Can be mounted on airsoft replicas with a 14mm CCW threaded barrel Compact Design Blast Mitigation Device Style Mini USB Cable Included Twist-Collar On/Off Illuminates Trace BBs but Tracer BBs are not required Aluminium Construction Lightweight: 100g Length: 6.8cm