Producing a full 130 lumens of brightness, the LED Smart Lamp clips on to the shade of most head magnifier (see related items below). Lower your head and the light illuminates; lift your head up and the light switches off, saving power. Has 3 brightness modes: 10%, 50%, 100% . Will work up to 18 hours on 10% brightness mode or 2.5 hours at 100% brightness mode. Easily re-chargeable with included USB cord. Measures 66mm x 27mm x 24mm (2.6” x 1.06” x 0.945”). Provided with instructions for use.