Remember when you didn't depend on cords to run your tools? Power your life with a WEN 20V Max Lithium-Ion 4.0Ah Rechargeable Battery. This battery is designed to fit the entire WEN 20V Max series, including model numbers 20107, 20135, 20121, 20401, 20405, 20630, 20625, 20653, 20944, 20496, 20200C, 49120, 49135, and 49120C. Lithium-ion cells create a fade-free power supply that provides 4.0 amp-hours worth of steady and consistent operation. Replace your current battery or add an extra for double the run time, keeping one on the charger and one in the machine. Forget the hassles of extension cords. It's time to simplify your life with an extra WEN 20V Max Lithium-Ion 2.0Ah Rechargeable Battery.