Specifications:
Voltage: 18V and 20V
Capacity: 3500mAh
Battery Type: Lithium-Ion

Replacement Part:
Replace for Worx 18v battery—— WA3512, WA3512.1 ,WA3511
Replace for Worx 20v battery—— WA3520 WA3525

Compatible Tool Models:
RW9161, WG151, WG151.5, WG151E, WG151E.5, WG155, WG155.5
WG251, WG251.5, WG251E, WG255
WG540, WG540.5, WG540E, WG540E.1, WG540E.5
WG890, WG891, WG891E
WU287, WU289, WU381
WX163, WX163.1, WX163.2, WX163.3, WX163.M
WX164, WX164.3
WX368, WX368.1
WX502, WX502.1

Battery Future:
1. High-capacity provide much longer runtime within a full charge, make your power tools more powerful.
2. No memory and low self-discharge. Can be charged or discharged as needed without loss of capacity.
3. Battery's energy density is higher than Ni-CD battery, make it smaller, lighter.
4. All battery have CE, FCC, RoHS certified. Tested by manufacturer to match or exceed the quality of OEM products, safer to use.
5. Battery doesn't contain harmful substance (Cd, Pb, Hg), protect your health, make no pollution to the environment.

Package:
1 x Replacement Battery
1 x User manual
Tips to make it running longer:
1. Battery came with low power due to transport security, it may reach top performance after 3 cycles of full charge and discharge.
2. Recharge the battery when it totally cool down and proper rest when use in high power tools.