blades for mower blades for lawn mowers MTD YARD MAN GUTBORD FOR MODELS CS53 , E478 , GES53 , GES53E , ROTOMAX53S , SUPER53S , VARIANT53SE MODEL - TECHNICAL SPECIFICATIONS LENGTH 533 mm CENTRAL BORE 21 mm OUTER BORE 10 mm CENTRAL BORE INDEX 63. 5 mm CODE: 13270099 ORIGINAL CODE 742-0621 , 942-0621 , 742-0521 , 742-0490 , 742-0306A , 742-0306 SR