This is a brand new Makita BL4040 40V max XGT® 4.0Ah Battery. It is designed for power tool and air tool accessories. The battery has a capacity of 4 Ah and uses Lithium-Ion (Li-Ion) technology. It operates at 40V and comes in the color black. The model number is BL4040 and you will receive one unit with your purchase. This battery is a great addition to your collection of power tool accessories.