This is a replacement weld in spindle for axles that run 6 Lug to 8 Lug Trailer Hubs and Drums. This is referred to as a #42 Trailer Spindle, which features a 1 1/4" Bering Surface and a 1 3/4" Bearing Surface. You can see the product pictures for exact dimensions of this Spindle. This Spindle includes the Spindle Washer, Castle Nut, and cotter pin.