Fit For the Following Models. This is a set of 2 track drive wheels for track series snow blowers. This is the rear drive wheel assembly on the track snow blowers and the hub size is 3/4. This all metal part is laser cut and welded. These Do NOT fit if you have a splined Axle Shaft. Specs 7 1/2 outside diameter 10 drive cogs 3/4 inch hub.