The Specialized Turbo SL Range-Extender Battery will eliminate your battery anxiety. This discreet and compact SL Range-Extender Battery provides up to 40 additional miles of mountain-flattening power to complement the up-to 80 miles of range from the Turbo Creo internal battery. More range means more riding. Specialized Turbo SL Range-Extender Battery Features 160Wh Capacity delivers up to one additional hour of riding. Compatible with Turbo SL Bikes. Includes a 3 LED charge-level indicator.