The Cateye Rapid 3 tail safety light includes a high power center SMD-LED and two 5mm LEDs for outstanding visibility. Three modes allow you to customize your visibility. The rapid mode is an all out attention grabber, using all 3 LEDs in a unique pattern guaranteed to get you noticed. The flashing mode foregoes the high-power center LED to save blinding your riding buddies, while the constant mode adds a daytime safety option. The included AA battery will run the Rapid 3 for up to 80hrs in flashing mode, 20 hours in Rapid mode and 3 hours in constant mode. It comes with the SP-11 FlexTight bracket that fits up to a 32mm diameter post.