The Grainger 16N581 is a 1/2 HP, 115V, 1725 RPM, 56C Frame, Open Drip Proof, Single Phase, Ball Bearing, Electric Motor. It has a NEMA standard 56C frame with a 1/2" diameter shaft and 1-1/8" long. The motor is totally enclosed, fan cooled with a Class B insulation and 1.15 service factor. It can be used for general purpose applications.