This combination brings together 18V MAX Output 4.0 Ah Battery (2-Pack) and 8.0 Ah Max Output Battery (2-Pack) to create a complete solution. RIDGID introduces the AC840040 18V MAX Output 4.0 Ah Battery (2-Pack). MAX Output batteries facilitate battery and tool communication unleashing the full potential of any RIDGID 18V Brushless Tool providing more power and more runtime. These batteries will provide up to 3X more runtime compared to the compact battery (AC870015). The Advanced Intelligent Electronics in MAX Output batteries enable users to power through the most demanding applications on the jobsite. The RIDGID MAX Output 4.0 Ah batteries are compact and lightweight, which reduces user fatigue. As always, these RIDGID MAX Output 4.0 Ah batteries are 100% compatible with all RIDGID 18V tools. Best of all, these batteries are eligible for the Industry's Only Lifetime Service Agreement, simply register within 90 days of purchase for FREE Parts, FREE Service, For LIFE. Charger sold separately. In addition, the RIDGID AC840081 18V 8.0Ah MAX Output EXP Battery 2-Pack delivers maximum power and the longest runtime for the most demanding work. The RIDGID 18V MAX Output EXP Batteries unleash extreme performance and are the best batteries in the RIDGID 18V system. Tabless cells create a more direct flow of energy to maximize power, runtime, and cell life while enabling faster charging. This kit includes 18V MAX Output 4.0 Ah Battery (2-Pack) and 8.0 Ah Max Output Battery (2-Pack).