SAT&Gaming Airsoft finds the 5KU Spitfire Tracer Unit fun to use. This uses an LED light at the front to simulate muzzle fire. It comes with a thread adapter that allows one to mount it from 11mm CW threads to 14mm CCWs. It has a bult-in rechargeable lithium battery with a battery level indicator and a full charge can light up 30,000 BB rounds.