This Hailong-1 downtube battery mount easily bolts onto the water bottle mounts of the bicycle frame. Installing this mount on your additional e-bike will allow for easy swapping of battery from bike to bike. If you have more than one e-bike, but can only ride one at a time, this makes a lot of sense. Buy additional mounts and move the battery to the bike you will be riding at that moment instead of buying additional packs. Mount get broken or damaged? Replace it with a new mount. Fits all Hailong-1 battery cases regardless of voltage, fits 36 48 52 volt, doesn't matter.