This Micro Click (a.k.a Micro Arcadian) features the Chimera driver which offers programmability and thermal regulation – unique for a driver of this size. It is powered by a 10440 battery (not included), incorporates a 12 mm LED mcpcb within a copper pill for superior thermal transfer. Nichia LEDs are used to take advantage of the larger smooth style reflector for a superior beam profile. Packing a big punch in a small package, the Micro outputs 650 lumens in a smooth beam. Titanium body 3.7 volt driver FET output Single Li-ion input only Designed to work with a 3 volt LED of choice. 12 mm board diameter at tabs 1,6 mm board thickness for improved thermal response