Five bright LEDs deliver great brightness with impressive runtime. The Omni 5 rear light provides 360 degrees of visibility and New Omni Directional Technology increases safety while three flashing modes – rapid, flashing and constant, let you select the right level of visibility. With two AAA batteries, the Omni 5 will run up to 120 hours. The simple, tool-free FlexTight bracket and included clothing clip allow you to easily attach the Omni 5 anywhere you'd like. Specifications Dimension: 36.0 X 75.0 X 21.9mm Weight: 41.8 grams (light unit and battery) Light source: Red LED X5 Battery: AAA alkaline battery X2 Runtime: Approx 60hrs in constant, 90hrs in flashing, and 120hrs in rapid mode Mount size: dia.12.0 to 32.0mm (FlexTight SP-11) Other: Clothing clip included *The factory-loaded battery life might be shorter than the specification above. *Design and specifications are subject to change without notice. Manual http://202.215.251.86/images/manual/TL-LD135-R_155-R_HP_ENG_v1.pdf