The Black+Decker® LB2X4020 20V MAX* 4 Ah lithium battery pack is Black+Decker® highest capacity battery pack for the 20V MAX* system of tools. The 20V MAX* 4 Ah pack has 2X the capacity as the LBXR2020. It packs a ton of power in one battery pack. This battery is designed to be compatible with Black+Decker® 20V MAX* platform of lithium-ion cordless tools and outdoor equipment. It is also backed by Black+Decker® 2 year limited warranty. Black+Decker® PowerSeries™ Stick Vacuum, 2-In-1 Cordless, 16 V