Battery Power: Equipped with two 21V / 4000mAh (4.0Ah) high-capacity Lithium-Ion batteries. [1] ( )Square Drive Size: 12.7mm (1/2") industry-standard anvil size. [1] ( )Maximum Fastening Torque: 330 N.m, providing sufficient power for automotive maintenance and heavy-duty DIY projects. [1] ( )No-Load Speed: Features an adjustable 2-speed setting: