We include an additional red sleeve in the packaging material for all customers. This sleeve is there in case you end up finding one more knife that you'd like us to sharpen. As per the instructions on the sleeve, you can simply send us an extra knife (or a pair of kitchen scissors!) in that sleeve, and we will invoice you via email once we receive/inspect your knives, and before we sharpen them. The extra knife is only $10, so it is well worth using the sleeve.