Fenix has updated the TK15. There are three differences between the new version and the old version.
*the LED has been updated from R5 to S2, improving the performance of TK15.
*there is a tiny change in the shape near the side switch, making tk15(s2) easy to operate, even with gloves.
*the tk15(s2) features dual recoil absorbing springs, increasing the impact resistance, while tk15(R5) with one spring on the tail.