Tips for purchase: Please make sure the battery type, voltage and model are compatible with yours. Please compare the shape and the appearance of the battery with yours to ensure they are the same. Please contact us first if you are not sure about the compatibility. Specifications: Voltage: 18V/20V Capacity: 8000mAh Battery type: Li-ion Replace for: Worx WA3520, WA3525, WA3575, WA3578, WA3511, WA3512, WA3512.1, WA3516, WA3523 Compatible with: Worx WG151, WG151.5, WG151s, WG151E, WG155, WG155.5, WG155s, WG251, WG251.5, WG251s, WG255, WG540, WG540.5, WG540s, WG890, WG891, WG180, WG170.1, WG170, WG166.1, WG166, WG165, WG163, WG160.4, WG160.3, WG160.2, WG160.1, WG160, WG157, WG156, WU287, WU381, WX163.