Shimano BM-E8020 Battery Holder for BT-E8020 250mm Steps Mount with Cable - New 4550170595357 | eBay
SHIMANO Steps Integrated Down Tube Battery Mount - BM-E8020, for Steps, for BT-E8020, W/O Key Cylinder, Battery Cable L=250MM, Battery Removal Direction UP/Down - IBME80201B