By using rare-earth magnets, engineers maximized the torque in Maxon's new RE series of motors. The motors measure just 15 mm (0.59 inches) in diameter and 22.5 mm (0.86 inches) in diameter and weigh 20 g (0.71 oz). They can deliver 300 mNm (42 oz-in) of continuous torque with a maximum speed of 11,000 rpm and maximum efficiency of 73%. Each applies Maxon's patented rhombic moving coil design to provide long life, low electrical noise, fast acceleration, and high efficiency. Maxon Precision Motors, Product Code 4170.