This is the complete internal saber core found in our top of the line EFX sabers. This saber core is complete and can be used to upgrade or repair any Crimson Dawn EFX saber. If you have one of our sabers with a V1, V2, or V3 core, this core will seamlessly upgrade your saber to the latest V4.
All you have to do is remove the old core and slide this one in its place. An 18650 Li-Ion battery is INCLUDED with this unit.