873800400 for Husqvarna Replacement Lock Nut  Seamless repair, highest performance - choose our parts now! Upgrade your outdoor tools with our replacement parts. Easy maintenance, excellent performance - trust the parts we replace for lawn mowers, lawn mowers, and chainsaws. We kindly request that you carefully inspect the appearance of the parts in the photos and compare them with the provided dimensions to ensure a perfect fit.Husqvarna Genuine OEM Replacement Quick Coupler - 503266003