Ryobi OP241A 24V 57.72 Wh Lithium Battery Pack Assembled dimension: 5.512 in. W x 7.402 in. D x 7.244 in. Back-up power for larger jobs For use with Ryobi 24-volt cordless tools, including RYU2420, RY24201, RY24600A, RY4061 and RY24601 Works with charger OP140A 1-hour quick charge