Keep your pen light bright. Compatible with COAST G20, G23, and HP4 pen lights, the ZX110 ZITHION-X™ rechargeable lithium ion battery features a built-in Micro USB port for easy charging outside the light. A battery charge indicator flashes red during charge-up and shines solid green when fully charged, and the overcharge/discharge protection circuits make powering up as simple and safe as possible. The battery is backed by COAST’s one-year warranty against defects in materials and workmanship.