I had thought that, at this price, the package would provided a wide range of diameters and thicknesses.  Instead there many sets of rings of similar sizes.  They are all very thin - thinner than any of the O-rings in my watches.  There are large gaps in the diameters provided.  It is unlikely that the size you need will be in this package.  If it is, then at least you will have about 20 in that size!  I needed two sizes and nothing from the package was even close to what I needed.

If they are going to sell something like this, then they should list the sizes - there are not that many to list!

This is a bad product at a very high price.