ONLY COMPATIBLE WITH 2025 SD MODELS The 20ah Battery Extension for SD models provides a significant range boost, increasing total battery capacity to 40ah. Designed to plug directly into the side of your bike&';s frame, this battery extension allows both batteries to drain simultaneously. The quick-release rear rack attachment makes installation simple and integrates smoothly with SD model bikes. This extension is incredibly valuable for riders planning long-distance trips or backcountry adventures who need extended battery life. The battery encasing is engineered to be compatible with our Rear Basket Accessory, adding versatility to your setup. Important: Only compatible with SD Models