The Arisaka 600 Series Light Body is designed as a streamlined replacement body for Surefire Scout Light M600 weapon lights. The 600 Series Light Body is manufactured without the mounting interface for the stock Picatinny clamp. This greatly increases the clearance for front sights when used in combination with the Arisaka Inline Scout Mount on handguards with 45 degree mounting surfaces adjacent to the top Picatinny rail. The 600 Series Light Body is compatible with Scout Light M600 series tailcaps and heads like the KM2C" KE2A and KX2C. IR heads are fully supported. It will also fit in any aftermarket Scout mount, as it retains the mounting holes and square lug interface on the underside of the light body. It is also possible to build a complete light from scratch by sourcing additional components. A variety of tailcaps and aftermarket light heads are available from online retailers. Our favorite light heads to pair with the 600 Series Light Body are the Malkoff E2HT and E2XT" which have much better beam profiles and higher candela than the Surefire offerings, and are made in the USA. The 600 Series Light Body is NOT compatible with the Surefire M600DF head or 18650 cells. 16650 cells are compatible.Features :Weight: 0.6 ozHardware: One #17 o-ring, one #15 o-ringMade in the USA