The CUBE POWERTUBE Adapter lets you convert your existing e-bike to use a smaller battery with less power and less weight. It’s perfect for securely installing a smaller battery without any annoying rattles. It even has a storage compartment you can use to carry keys or other small tour essentials safely stowed away. Use this adapter if you want to use a 500 Wh battery instead of a 625 Wh battery or a 625 Wh battery instead of a 750 Wh battery.