MTD, Yard Man, Gutbrod Adaptable lawn mower blade for lawn mower mowers Models 508 N , 529 B , GF56 , SP56 G , SP56 SD Features: Length (mm): 557 Centre hole (mm): star, 4-point Outer hole (mm): 8 Centre-to-centre distance (mm): 63.5 Weight: 710 g Part No. : 13271382 Part No. : 742-0742A, 742-0742 MTD , Yard Man , Gutbrod SR m