Highlights: Press right button. Book light turns on. LED light is bright Use metal clip on any object. Move topmost link to adjust bright degree to the best lighting result Take back, press back topmost link backward, press lowest link forward Use 3 (AG13) batteries (not included) Specification: Function Mode: On/ Off Battery: 3 x AG13 batteries Dimensions (cm): 11.7 x 3.5 x 1.9 Shipping Weight (kg): 0.0481 Package Contents:1 x