Its a tin that contains really strong (British, I believe) breath mints. You can purchase them at any drugstore. They're with the candy and other sundries at the checkout counter.
When empty, the tin can be used to store things--like used DE razor blades.
You can also purchase a DE blade tin online from some of the vendors who advertise here at SRP for $0.99.
The Altoids tin is a cheaper alternative, though.