Patented and tool integrated EZ Change mechanism for quick and easy accessory change * Patented EZ Lock and EZ Drum mechanism for quick and easy change of wheels and sanding bands * The highest value rotary tool kit with most assorted variety of attachments and accessories in a premium metal case * Highest performing Dremel Rotary Motor with 20-percent more venting for cooler running * Variable speed and electronic feedback to keep speed constant under load and avoid stalling