FREE SHIPPING Razor +5 speed booster kit adds 5mph top speed and more torque (battery not included)
Use any brand high power thick wire "nimh" 7.2 volt r/c battery with Tamiya connector
3000 MAH and up
how to install video's on youtube/mykwilwin
I also have these listed on Etsy https://www.etsy.com/listing/253390411/razor-mx500-mx650-speed-booster-5-kit-mx?ref=shop_home_active_4
Ships from Tustin, CA. with USPS.
Here's more info on Pocket bike planet,