Abrasion protected high power motor for increased durability. Dust sealed bearings and components for a long product life. Full power variable speed electronics with constant speed control. Heat treated precision gears for smooth power transmission. High-flex cable for maximum flexibility and long life. Spindle lock for quick wheel changes. Cut-off brushes to prolong motor life. Brush access window for better serviceability. Top rubber bumper to protect from scratching the work piece.