This is Husqvarna's 300-3T Multi Grass Blade 578444501Fits the Following Models:135R, 142RB, 142RJ, 143R, 143R-II, 152RB, 152RJ, 153R 235FR, 235R, 235R-II, 236R, 240F (2007-Present), 240R (2007-Present) 241R, 250R (2007-Present), 252RX (2007-Present), 253RB, 253RJ 333R, 335FR, 335RX, 336FR, 336FRD, 343F (2007-Present) 343FR, 343FRM 343FRM, 343R, 345FR, 345FX (2007-Present), 345FXT (2007-Present), 345RX 355FRM, 355FX, 355FXT, 355RX, 535RX, 535RXT, 543RS, 543RBDX, 545FX, 545FXT, 545RX, 545RXT, 553RBX, 553RS, 555FRM 555FX,555FXT, 555RXTSpecs:1" Arbor Size 3 Prong Blade
