Milwaukee 12V Li-Ion Battery 4.0AH M12B4

Features:

REDLINK PLUS Electronic Intelligence enables advanced communication between your batteries and tools, allowing for unmatched levels of performance, protection, and productivity
Fuel gauge onboard displays remaining runtime for less downtime on the job
Powers more than 50 MILWAUKEE M12 cordless power tools
Best-in-class construction offers long lasting performance and durability

Specifications:

Voltage: 12V
Battery Capacity: 4.0Ah