This is a Malkoff Devices 2-3-4 D Dropin Module. It has a Seoul SemiConductor P4 white LED. The output is 700ma (150+ lumens) at 3v, 1000ma (240 lumens) at 4.5v, and 1100ma (240+ lumens) at 6v. It is a Dropin replacement for 2,3, or 4 cell D sized Maglites. The runtime is fully regulated at the specified current for 8+ hours in a 4D. It will continue to run at decreasing current for 2-3 days.