Specs: ID: 7/8″. 1 7/8″ for outer pins from center to center. Compatible with/Replacement for OEM Number: AYP: 850977, 581547901; Husqvarna: 532850977. Fits: 20″ walk behinds, 1994 and newer, 20″ walk behinds, 1994 and newer. Stens one-year warranty ensures reliability and performance for every part. Stens branded parts are trusted by professional dealers to perform OEM quality repairs.