A single AAA battery offers the i3T 2 EOS small everyday carry flashlight a max power of 200 lumens output; the 10440 rechargeable li-ion battery (not included) is also supported and can boost the light's max output to 300 lumens. The clip on the i3T 2 is now stuck between the battery cover and the body- never worry about falling off and it allows for deeper pocket carry. Both soft and heavy activation can be set default mode by simple operation, making it more obey to your will. Compared with the i3T, this 2nd generation gets 31% more battery life, and 71% more runtime in High mode. We optimized the circuit to ensure its surface temperature less than 113F even during long-time work.