BLADE HUB Compatible with HUSQVARNA lawn mowers for PROFLEX 18/20, RIDER 11/13/13R/15V2/16/16H/850/850HST/850HJST PRO/970/PRO14/PRO15 MODELS CHARACTERISTICS: Shaft diameter: 20.1 mm Insertion depth: 15.3 mm Reference code: 30-708 Original part number: 506 53 41-01 HUSQVARNA