Princeton tec quad tactical head lamp interchangeable lens aiming to meet the highly specialised needs of outdoor sportsmen and the us military princeton tec has introduced a tactical version of the popular quad headlamp this augments the original quads lightweight and durable design with three interchangable lens covers which filter the four ultrabright regulated leds into red blue or green light features 3 x aaa alkaline batteries or lithium 4 output modes high medium l