This Zoll 8019-0535-01 SurePower rechargeable lithium-ion battery pack is a perfect companion to your AED Pro or R / E Series unit! The battery pack is an important part of your AED and gives it the power needed to administer shocks to a patient. It is designed to be recharged with the compatible charging station (sold separately), allowing you the convenience of charging a used battery back to full instead of purchasing a new non-rechargeable pack. This battery features a life indicator that also displays the approximate run time, instead of a capacity that doesn't translate to an immediately useful figure. It also records the use and maintenance history for the battery.Part No : 8019-0535-01