US Stamp: It all Depends on Zip Code. This unique stamp features an image of a letter with different zip codes circled in red. The stamp represents the importance of zip codes in the United States and how it affects the delivery of mail and packages. A great addition to any stamp collection, this stamp is a perfect way to commemorate the postal system in the US. Designed for collectors, this stamp is in mint condition and has never been used. Get your hands on this one-of-a-kind stamp and add it to your collection today!