Kellermann's BLACK High Power LED Technology: Longlife Protection Guard®, IC controlled, 330 kHz clocked. This circuit, together with other measures, ensures that the LEDs achieve their possible lifespan, with maximum brightness and minimum power consumption. The Bullet 1000® Collection: This collection features Kellermann-HPT®(Homogeneous Projection Technology) for uniform, spectacularly bright light output. Features a BLACK, high-quality metal case with a maximum diameter of 39mm (1.53"), so it looks as discreet as jewelry when mounted. Available for front and rear lighting variants.