GLL&reg; Battery Operated Lighted Magnifier Desk Lamp with Flexible Gooseneck,Magnifier Reading Lamp,Battery Powered Reading Light,Table Lamps for Bedroom,Adjustable Brightless Book Light(Black) Two levels brightness set: on/off swtich design of the usb light, just turn on the switch for twice, the light level can be adjuable Flexiable metal tube: free angle twistable neck to put the light anywhere as you like The lamp can be power by 3 x AAA battery, and also can be power by usb ,it can connect to computer /laptop/power bank/ usb charger adapter. With 18 led bulbs,power saving design of led light up to about 50000 hours of usage Triple magnifier design, which is a idea gift for old friends.