The Campbell Hausfeld PU017001AV Air Compressor Motor Drive Pulley is a replacement component designed for compatible Campbell Hausfeld air compressors. Measuring 3.45 inches in outside diameter with a 7/8-inch size, it helps transfer power from the motor to the compressor pump for proper operation and reliable performance. Replacing a worn or damaged pulley can help maintain efficien... https://www.wholetoolbox.com/campbell-hausfeld-pu017001av-air-compressor-motor-drive-pulley-3-45-od-x-7-8/PU017001AV.html