This light head is a direct replacement for the Surefire M600DF head. It can be used with the Modlite 18650 body or the smaller Modlite 18350 body. While lumen output is only 680 lumen the throw is about 400% greater than the M600DF. This light head is best suited for situations where extreme throw is needed.Hand assembled in and tested in the USA.Lifetime guaranteeApproximately 680 out the front lumens and candela is approximately 69,000. This light is an excellent choice for anyone needing maximum throw.Drivers are fully potted and tested to withstand select fire SCAR 17 recoil.6061 Series Alum bezel with Mil-Spec Hard Anodizing.Ultra clear BOROFLOAT® lens allows 98-99% light transmittance.