This is an optional ST Racing Concepts Aluminum Battery Strap, intended for use with the Traxxas Slash. Add more strength and battery position adjustability to your Traxxas Slash with the ST Racing Pro Racing CNC Machined aluminum battery strap. Those that run Lipo batteries have difficulty moving the battery forward and putting the foam spacer behind due to the design of the stock plastic battery strap blocking the battery plug. For better weight distribution while running lipo packs and for more handling tuning, moving the battery forward while running a lipo pack can help with better steering and overall weight balance on the Traxxas Slash. The ST Racing battery strap also allows for better access for lipo batteries that have plugs that comes out from the side of the pack.