Nighttime combat wildly comes alive with incredible cinematic effects when you can distinctly trace projectile beams illuminating the darkness. Install UV LED technology on your replica's muzzle with minimal effort: Airsoft Tracer Units for red/green phosphorescent BBs (Standard 14mm CCW mount or 11mm reducers for GBB Pistols). Internal flashes brutally activate the BBs phosphor coating, creating a lethally spectacular tactical display.