These Teflon discs do what they should. I haven't had them long, so I don't know how they will hold up long-term; but they work. The reason I gave four stars instead of five is because of how they are cut. They are not perfect discs. They look like they were cut - poorly - by hand. In this day and age, when you can purchase a dollar-sized hole punch at any craft store, there should be no excuse for having odd-cut "discs". There wasn't a "disc" in the bunch. They were oval-ish in shape and no two were the same size or shape, so there isn't any consistency of how they look, (which isn't that important since no spectator will ever see them), or how much of the shell interior they cover. I even had to trim a couple up myself.
So, the product does what it should; bit they are poorly and inconsistently cut from disc to disc.

First class item they make my splip coins so easy to use

I got a ton of these for my slippery shell sets. You get a little tiny package with these in them, and you can put them on your shell set. They are made to make the shells slide easier and they do. They really work. And 10 is more than enough if you use them properly. BUY NOW!

Applied them to my £2 split coin bought from eBay, and it works perfectly!
Stick the teflon to the coin, then use a sharp cutter to trim them to fit easily.
Remember to buy the dollar size version because the half dollar size version is at the same price.
You need to cut them to fit anyway.

They should be WHITE so as to not show as much, but they do keep the chatter to a minimum.

These work perfectly. The coin slides smoothly. However, the pieces are not cut perfectly nor rounds. One should expect to trim.

Exactly what I was looking for. Deducted 1 star because I did have to hand trim them to fit my coins, prior to applying them.

The Tango Teflon Circles, in my opinion, are far and away the best Teflon liners available for coin shells on the market today! Easy to apply and work great!

Teflon Circles are large enough to cover the coin face, edge to edge and not just inside a shell. That being said, the discs are not perfect circles. I thought they were “punched” into perfect circles, but they quite imperfect which means trimming is a must.
My suggestion: place your Coin / Shell on the disc and use a fine point sharpie and trim the excess imperfections with scissors. For shells cut slightly inside the sharpie line.
Tango would help everyone if they came “square” allowing ample marking and trimming (plus its gotta be easier for Tango too and less trash to disposal).

Some comments mention that the circles are a bit big or ill shaped. They are, but it is a plus because when applied it may be off-center just a bit. Since it would be difficult to reapply, it is better that they can be trimmed after they are put on. And they work well. I use a small amount of 3M Dry silicone for maintenance.