Busch + M&uuml;ller Lumotec IQ Cyo T Premium Senso Plus 80 lux LED bicycle dynamo headlight 80 Lux main LED plus 4 daytime LEDs for improved visibility Integrated sensor automatically switches the light on in low-light conditions Standlight function keeps light on while bicycle is stopped at traffic signals On / Off switch overrides sensor and standlight functions Designed for 6 volt, 3 watt dynohubs only; cannot be used with batteries