The Amp 3.0 defies size perceptions with 40 lumens of pure white light in a compact & rugged Xylex housing. The impressive brightness is courtesy of the latest Nichia Ultrabright LEDs boasting 30% greater output than standard LEDs. Combine this with two output settings and a regulated circuit, and you have 90 hours of glorious illumination. Burn time: 90 hours. Weight: 122 g. Lumens: 40.Runs on 4 AAAs with (4) 5mm Ultra Bright LEDs.