for Milwaukee M12 Battery : Features: 1.Battery Type: Lithium-ion / Voltage:12V / Capacity: 6.0Ah / 9.0Ah 2:Compatible with all Milwaukee M12 cordless power tools 3:Premium connector provide steady currect ,a good connector to your tool ,easy to install and remove 4:The ABS+PC plastic material,durable enough to protect the cess inside battery and prevent the damage from outside 5:Over-Charge protection / Over-discharge protection / Over-current protection / Short-circuit protection for Milwaukee M18 Battery : Features: Battery Voltage: 18V/ Battery Capacity: 6000mAh / 9000mAh/ Battery Type: Lithium-Ion Compatible with Milwaukee 18V Cordless Power Tools and Chargers Electronic control charge and discharge analysis to optimize performance and extend service life.