The Milwaukee M18 REDLITHIUM XC5.0 Extended Capacity Battery Pack in black is a high-quality lithium-ion battery with a capacity of 5 Ah, designed for power tools and workshop equipment. With a voltage of 18 V and a compact design of 2.8 inches in height, 4.5 inches in length, and 3.1 inches in width, this battery pack is lightweight at 1.54 lbs. The Milwaukee 48-11-1850 model offers reliable performance and long-lasting power for various home and garden tools.