Honda OEM Replacement Blade 325-013 
FITS MODLES: Harmony, Harmony II, HRB215, HRM215, HRS216 and HRT216 with 21'' decks
Upper mulching blade 
Length 21'' (533.4mm)
Centre Hole 1 1/4'' (31.8mm)
Outer Hole 13/32'' (10.3mm)
Centre 3 7/16'' (87.3mm)
Width 2 3/4'' (69.9mm)
Thickness .120'' (3mm)