The Etek ET-R represents the highest power/weight/dollar available on the market for brush PM motors. Designed and built by the same team that brought us the original E-tek motor. 3 lbs heavier (28lbs), this radial motor can do 100 amps at 48 volts continuously (300amps for 1 minute) and runs in either direction. The max recommended rotor speed is 5000 rpm. This is ideally suited for 24-48 volts. Torque constant of .13 Nm per amp. Works with the Alltrax SR controllers or the Sevcon 4Q for built in reversing. Great for electrathons, motorcycles, and go-carts.