The RYOBI™ 18V ONE+™ System introduces lithium-ion performance at Ni-Cd prices. The 18V ONE+™ Compact Lithium-ion Battery provides up to 20% more runtime, holds a charge 4X longer and is 45% lighter weight than 18V ONE+™ Ni-Cd batteries. Best of all, like all 18V ONE+ batteries, it works with over 70 great ONE+™ tools. This two pack of lithium-ion ONE+™ batteries is a perfect addition to any ONE+™ collection.