BEST PERFORMANCE and PERFECT COMPATIBILITY: Fully compatible with the original charger and tool.It's easy to install . TRUST WORTHY RELIABILITY: No memory effect,Low rate of self-discharge (1% per month) .Patented battery balancing technology,Built-in over protection circuits provide safety and reliability from fire and explosion. GREAT SAFETY: Quality battery cells with CE and UL approval. Applicable to Worx tools: WX125, WX382.2, WX382.3, WX540.3, WX677, WU025, W125.1, W125.3, W125.4, W125.5, W125.M, WX126, WX128.2, WX382, WX382.4, WX382.7, WX382.M, WX382.M1, WX382.M2, WX521.1, WX521, WX521.1, WX540, WX673, WX673.3, WX673.M, WX677.7, RW9300, RK2510K, RK2510K2, RK2515K2, RK2516K Strong warranty: We guarantee to provide a safe and full capacity replacement battery. We also provide you with a 100% risk-free satisfaction guarantee. 30-day refund and 12-month warranty.