Lvbu BY20D 20 inch ebike conversion kit with bottle battery
simple and beautiful design/Portable battery/Easy installation/Concealed battery /hidden battery /18650 power lithium ion battery/36v 250w/36v 350w/bluetooth connection/Smart assist system/hidden controller/easy to fit/pedal assist/bottle battery design/outdoor cycling/overspeed alarm/16 inch/20 inch/24inch/26inch/27.5inch/29inch/700c