blades for mower blades for lawn mowers MTD YARD MAN GUTBORD FOR MODELS 476 , 487 , 490 , 494 , 496 , 497 , 498 , 720 , 760 , RD51 , REX-COMBI51 MODEL - TECHNICAL SPECIFICATIONS LENGTH 508 mm CENTRAL BORE 9. 5 mm OUTER HOLE 7.9 mm CENTRAL HOLE INDEX 63.5 mm CODE: 13270751 ORIGINAL CODE 742-0100 , 742-0123 , 742-0128 - 742-0187 SR