The product is a genuine Milwaukee RedLithium M12 4.0 Battery XC4.0, featuring a lithium-ion technology with a capacity of 4Ah and a voltage of 12V. This model, designated as 48-11-2440, is designed for use in power tools and workshop equipment. Milwaukee is a trusted brand known for producing high-quality batteries for various home and garden tools, making this product a reliable choice for those in need of a durable and efficient power source for their tools. Customer purchased a combo kit from us and used it for about a week, and then sent it back.