The 38mm Apple Watch replacement battery is compatible with Series 1 A1802 and (first generation) A1553.(Apple Watch Sport,Apple Watch Edition,Apple Watch Herms are also compatible).Battery life not as good as it used to be? Replace your Apple Watch battery and buy yourself more time.This new battery for Apple Watch is only available in 38mm Apple Watch Series 1 and all (first generation) models.Product Type: Lithium Polymer,Voltage: 3.8V,Capacity: 205mAh / 0.76Wh Each Apple Watch battery is tested by professional testers in accordance with strict quality control standards and tested in good condition before shipment.After purchase,we will send an Apple Watch battery kit repair tool set (3 x screwdriver + 2 x removal lever + 2 x triangle piece + 1x metal triangle opening tool + 1x screen adhesive) as a gift Battery replacement A1578 with repair tools Kit for S1 Apple Watch Series 1 A1802 and (1st generation) A1553 38mm