The ET-RM is a Permanent Magnet, Brush Type, DC Motor with Neodymium Iron Boron Magnets. 90% efficiency. The 1" shaft is similar to the shaft on most Lawn and Garden Tractor engines. Perfect for an engine replacement on a Lawn and Garden tractor when converting the tractor to electric propulsion. Capable of 200 amps continuous, and 400 amps for 1 minute. Works with the Alltrax SR controllers or the Sevcon 4Q for built in reversing.