The Nitecore Thumb LEO has a maximum output of 45 lumens white light and is powered by a built-in, rechargeable, Li-ion battery. The Thumb LEO is a UV version of the Nitecore Thumb and features the same tiltable head, rechargeable battery and screw fastened clip. However, the LEO keyring torch, offers one LED of white light at 45 lumens and a second LED of 500mW UV light. The UV and white lights are operated using the button closest to the head; simply click once for the white light, again for the UV light and a third time to turn off. The button towards the end of the torch activates the red/blue flashing signal on top of the torch. The Nitecore Thumb LEO is extremely useful to attach to a breast pocket or sleeve, as the 120 degrees tiltable head can be adjusted as required. The flashing signal is ideal for increasing visibility and ensuring people are aware of your presence.