Milwaukee brushless motor: optimized for efficiency, this motor delivers more run-time and longer life than a brushed motor REDLINK™ Intelligence: Advanced overload protection defends against abusive applications and monitors the temperature to prevent damage and ensure maximum tool & battery life. REDLITHIUM™ batteries (not included) deliver more work per charge and more work over the life of the battery Paddle Switch Design for Increased Comfort and Ease-Of-Use when Operating in Various Positions Tool-Free Guard Adjustment for faster guard installations and adjustments 5/8"-11 Spindle for Use with Common Grinding Accessories Overload Protection: Maximizes motor life Electronic Clutch for Kickback Protection Compatible with all M18™ batteries