I have a 36 inch Wright Stander commercial mower - look at the photo of the mower because I have seen more than one reviewer who had no idea what a Wright Stander mower is or what he looks like. My Wright's front wheels are 11" x 4" with a 3/4" axle bolt. The wheel hub in the center of the wheels needs to be full width and these spare wheels are centered but not full width on the outside of the tire sidewalls, so I needed spacers. The seller includes 2 size 4 cheesy plastic spacers 3/4 inner diameter. I needed a thinner plastic washer and the original washer from my original wheel to get these wheels working on my car. I will be watching how they work wear out over time and when I see the plastic seals wear away I will replace them with custom made 3/4 brass seals.Brass is much harder than plastic, self lubricating and easy to cut.These wheels also come with two sets of metal bushings The first set is installed into the wheel hub, marked 'M' and is 3/4" ID. The additional pair of metal bushings is marked with a "Z" and has a 5/8 ID so both cannot be used with a 3/4 axle unless you have the 5/8 "on 3/4" drilled. The bottom line is that "easy installation" is not a 100% accurate term with these wheels. So when you have a Wright Stander lawn mower, be prepared for the little things. Hope that helps!