Coutax OEM Replacement Blade 305-0779 
FITS MODELS: 16000100, HGM machiens, 36'' (0.91m) and 42'' (1.07m); Mulchign blade
Length 14 1516'' (380mm)
Centre Hole 3/8'' (10.2mm)
Width 2 15/32'' (62.8mm) 
Thickness 5/32'' (4mm)