Samsung manufactures some of the best li-ion cells on the market, and the Samsung 40T is no exception. It features "Maximum Balance" with very high capacity and ultra-high discharging/drain capabilities. Having 4,000 mAh in capacity with a 25 amp true constant discharge rating without involving a temperature limit cutoff and not making the cell overworked is spectacular.
Do no use with e-cigarette, vaporizer, or similar device.
Good price on a highly recommended battery