The chromium oxide is applied in small quantity to a leather strop to get a sharper edge after the honing proses or after the use of your straight razors/knifes. It works great and with little effort consistent results can be achieved. Below is a great explanation of how best to apply the chromium oxide to your strop.
I do also sell Chromium oxide crayons but they work best on the cotton side. Don’t apply a thick layer of chromium oxide since even a small amount will be sufficient. There is no reason to cover your strop in a thick layer of Chromium Oxide that might have a negative effect if you are a beginner trying to learn honing.
20g of Chromium oxide 0.5 micron.
Overseas buyers are welcome.