Rotary 13024 Mulching Blade Replaces: Husqvarna 580244001, 580244002 Length 21-15/16", Width 2-1/2", Center Hole DIA Star, Thickness 0.15" Fits: HUSQVARNA: HU550F, HU550FH, HU675FE, HU700F, HU700L, HU725AWD, HU800AWD Does not fit models with Brake Blade Clutch (BBC) feature