Set of three (3) replacement aftermarket USA made blades by Copperhead / Rotary that fit 52" Cut Ferris Mowers, 3 for 52" cut . These blades are 18" long by 2-1/2" wide with a 5/8" center hole and .204" thick. 
Blade specifications as follows:
Overall Length: 18"
Width: 2-1/2"
Thickness: 0.204
Mounting Hole: 5/8 Round
 
Also fits:
BAD BOY: 038300000
ENCORE: 363291
GRAVELY: GDU10231, 00450300, 03253800, 0450300
GREAT DANE: D18037
LESCO: 050125
SCAG: A48108, 48108, 481707, 482462, 482878
SNAPPER/KEES: 5101756, 5101756SYP
TORO: 133-2134
WINDSOR: 50-2148, 50-2295, 50-4215
WRIGHT: 71440001