Fangrui Product Details Accessories Made Of Material The Dual Battery Parallel Module Manages Two Battery Packs On Your Bike And Supports Two Batteries At The Same Time To Provide Smart And Balanced Power To Your E-bike. Attention: 1. The Voltage Range Of The Two Batteries Cant Be Too Different, If The Controller Doesnt Support The Wide Voltage It Is Easy To Damage The Device, The Capacity Of The Batteries Can Be Different. 2. If You Need To Use Different Voltage Battery Packs, First Please Make Sure The Controller Supports It, If It Does Not Support Multi-voltage Please Be Careful To Buy. Size: 128 X 80 X 45mm Material: Composite Materials Colour: Black Package Contents: 1 X Scooter Controller Only The Above Package Content, Other Products Are Not Included. Note: Light Reflection And Different Displays May Cause The Color Of The Item In The Picture A Little Different From The Real Thing. The Measurement Allowed Error Is +/- 1-3cm.