The M12 FUEL? HACKZALL? is the fastest cutting and most powerful saw in its class, delivering over 4X more run-time, up to 70% faster cutting, and up to 6X longer tool life than competitive saws. The compact, one-handed design provides superior control and the ability to make cuts in tight spaces. Its? light weight design is optimal for overhead cutting applications. The POWERSTATE? Brushless Motor outperforms all leading competitors with constant power output, yet runs cooler with no wearable components. REDLINK PLUS? Intelligence ensures optimized performance and protects your investment from overload, overheating, and over-discharge. The M12? REDLITHIUM? XC4.0 Battery Pack (not included) provides more work per charge and more work over the life of the pack than competitive batteries. The dual gear counter balance mechanism significantly reduces vibration, providing faster starts in metal and reduced user fatigue.