Runs longer with Worx PowerShare Pro 4.0 Ah batteries, offering 2X the runtime of 2.0 Ah batteries. Compatible with all Worx 20 V and 40 V cordless power tools, outdoor power equipment, and lifestyle products. Runs cooler and runs longer thanks to advanced thermoplastic keeps cells cooler. Extended lifespan thanks to 360° cell protection, providing increased security against vibration and impact. Intelligent battery management system enhances power output, performance, and runtime by optimizing individual Li-ion cells. Charge-level indicator quickly lets you know how much charge remains. Push-button release easily disengages battery from tool. Compatible charger models: WA3742, WA3769, WA3881, WA3770, WA3884, WA3835.