The DEWALT DCB1102E2 XR POWERSTACK(tm) Starter Kit contains the following: 2 x 18V 1.7Ah DCBP034 XR POWERSTACK(tm) Slide Batteries. The DEWALT DCBP034 XR POWERSTACK(tm) Slide Battery is 25% smaller and 15% lighter than the DEWALT DCB183 18V XR 2.0Ah battery, making it easier to use in tight workspaces. Stacked pouch cell battery technology provides a low impedance construction, meaning the rate of flow of electrons is much higher thanks to the innovative internal pouch battery connectors and electrodes. Providing a greater surface area vs a traditional cylindrical battery cell type. It also benefits from superior thermal performance, vs cylindrical batteries. This increases battery durability, improves the cycle life and results. Works with the complete line of 18V XR tools .