Great 8 AA battery holder for your Arduino project! Provides 12V output when used Alkaline batteries, 9.6V when used with rechargeable AA batteries. These AA battery holders feature a standard 9V snap connector. The case is made from ABS plastic with nickel plated springs to hold your AA batteries in place. Each battery holder measures 2.5" x 2.3" x 1.25"( L * W * H ). AA batteries in these holders will last much longer than a standard 9V battery will when powering up electronic projects. AA batteries not included. These battery holders will also replace the holders in many different electronics devices that may have been damaged by corrosion.