Set of three (3) replacement Heavy Duty blades that fit 52" Exmark Decks that have 5/8" arbors and require blades with 5/8" center holes, 3 for 52" cut . These blades are 18" long by 2-1/2" wide with a 5/8" center hole and .240" thick. Made in USA by Rotary Corp. Blade specifications as follows: Overall Length: 18" Width: 2-1/2" Thickness: 0.240 Mounting Hole: 5/8" Round Note: Decks that use this dimension blades have used two different center mounting holes, this one with 5/8" center holes and the newer versions that use 15/16" center holes. These blades will not fit the newer decks, we have them listed in our store.