Park Tools are the best for bikes. I give this 5 stars because Park does not hide the fact that the older stands are larger diameter. It isn't really optional. If you don't have this kind of collar to mount the wire frame, you won't get it to work or look right. This part works, it does what it is supposed to do, and mounting it on an older stand is EASY. I ordered the nicer work tray for my PCS-1 bike stand to replace the old broken tray. I've had my bike stand for many years and a few moves, so it has taken a beating, and works just great for adjusting and repairing the bikes. I saw a review with one star complaining that this wouldn't fit the old style stand without modification, but I bought it anyway. Sometimes you're blessed to ignore the whining of others. Yep, it doesn't fit the old stand right out of the package, but the modification is not rocket science. The part is made of thick hard flexible plastic, so it does not have to be milled like metal. If you take a dremel tool with a little sanding attachment, it takes about 5 minutes to sand out the inner diameter about a sixteenth to and eighth of an inch and you're good to go. You could use a sanding drum on a drill if you don't have a dremel. A rat tail file would work. It isn't hard to figure out. The material is easy to remove, and the collar is thick enough that removing a little does not compromise it's function. The quick clamp works just fine, and it is really nicer than the shallow tray. Tools used to slide off that old tray. This one is large enough for a magnetic bowl to catch the metal stuff and keep it handy. The wire frame and extra holder for towel and lube is great. We Love Amazon!