Ecology meets economy. The CatEye Econom Force uses ROL technology and 4 AA batteries to provide an efficient, regulated 4000cd light beam. With high, low and flashing beams, a run time of up to 30hrs, and the option of upgrading to NiMH rechargeable batteries, using the built in charging port, give you as many lighting options as you have needs. Specifications Dimension: 114.0 X 56.0 X 53.0mm Weight: 244 grams (with bracket and batteries) Light source: High power white SMD LED X1 Light output: 4000cd Battery: AA alkaline battery X4 Runtime: Approx 2hrs in high mode, 9hrs in low mode, and 30hrs in flashing mode Other: Low battery indicator *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/HL-EL540_ENG%20v3.pdf CATEYE 2014 Headlight Chart http://202.215.251.86/data/resources/hl_chart14.pdf