Compatibility - 36V 12 Ah (Stnadard Range) Battery replacement for all versions of the Razor MX500 and MX650 Dirt Rocket electric dirt bikes Premium Branded Batteries - AlveyTech battery packs use Universal Battery (UPG) brand batteries, leading suppliers of battery and power-related products in the United States for over 50 years Safely Packaged - To prevent damage, battery packs will not be shipped pre-assembled and will ship with protective terminal caps. Wiring harness will need to be installed. Instructions included Maximize Performance and Lifespan - Top charge prior to first use, keep charged even during periods of storage, don't overcharge, and use manufacturer recommended charger Verify Model Version - Check your Razor 19-digit ID, the 7th and 8th numbers in your product ID code are the version number of your Razor product (e.g. "01" = V1, "09" = Version 9, etc.) Manufacturer Part Numbers - W15128190003 / UB12120 Ease of Mind - Rechargeable, maintenance free, valve regulated, easy to handle, spill proof, Sealed Lead–Acid (SLA), utilizes Absorbed Glass Mat (AGM) technology. UL Certified: UL 2271 12 Ah replacement batteries with wiring for the Razor MX500 and MX650. This battery pack is a compatible replacement for both the Razor MX500 and MX650 electric dirt bike. It includes the wiring harness and instructions on how to install the wires.