Battery reached the end of its cycle life? Need that high setting but a single battery can't last long enough? Solve problems like these with the STEELMAN PRO 78626 Custom Interface Replacement 18650 Li-Ion Work Light Battery. Built with an integrated custom single-contact interface not found on standard 18650 rechargeable batteries, this lightweight power cell can replace either a dying battery whose charge cycles are used up or can be easily carried in a pocket or work bag and swapped out when the current battery's charge runs low. Useable with STEELMAN PRO work and inspection lights model numbers 78606, 78708, 78952, 79057, 79419, 96792, and 96883. Not compatible with the STEELMAN PRO 60720 Slim-Profile Motion-Activated Headlamp. See replacement battery part number 60660 for that headlamp.