Copperhead Mulching Blade with 5 Point Star Hole replaces Husqvarna 580244001 (replaces 580244002) 4 n1 Mulching Blade. Fits models HU550F, HU550FH, HU675FE, HU700F, HU700L, HU725AWD, HU800AWD. For Husqvarna 22"Walkbehind models. (See Rotary 13023 for Std. Blade). Does not fit models with Brake Blade Clutch (BBC) feature.