CastleGarden OEM Replacement Blade 305-0569
FITS MODELS: MAC 48cm, McCulloch 
Lenght 18 9/10'' (480mm)
Centre Hole 3/4'' (18.5MM)
Outer Hole 11/32'' (8.75mm)
Centre 2 9/16'' (65mm)
Width  2 3/8'' (55mm)
Thickness 5/32'' (4mm)