FitBest Carburetor for Husqvarna 51 55 Chainsaw Replaces Walbro # 503281504 WT-170-1 New quality replacement carburetor produced by OEM factory Replaces P/N part #: 503281504, Fits Husqvarna 51 55 Chainsaw, Walbro #: WT-170-1 WT-170 Package includes 1pc x carburetor, 1pc x gasket