Diameter 58 mm 58 mm 58 mm X Stock Number: Light colour: Cold white (approx. 8000 K 158614 158620 158628 Light colour: Warm white (approx. 3000 K) 1586141 1586201 1586281 X Illumination value: 4000 lx [...] of the reading area. To switch on the built-in LED lighting please press the button w. After approx. 30 minutes the lighting switches off automatically. If, after this time, you want to continue using [...] using the lighting press the button w again to switch the lighting back on. 3. After approx. 30 minutes the lighting switches off automatically. As a result of this, unnecessary depletion of the batteries