Zebralight H600Fw Mk II Floody 18650 XM-L2 Headlamp Neutral White PID thermal regulated outputs (1020Lm and 620Lm) Battery: One 18650 size (up to 69mm long) 3.6/3.7V li-ion rechargeable. Batteries are not included. Automatic stepping down from High to Medium, and from Medium to Low when battery capacity is low Builtin over-discharging protection (2.7V cutoff) Smart user interface provides fast and easy access to all brightness levels and beacon-strobes.