Plastic Sealed Stamp Perforation Gauge

Plastic sealed stamp perforation gauge. The purpose of a stamp perforation gauge is to measure and count the number of perforation on a stamp. Like coin varieties, seemingly identical stamps can also have minute differences that distinguish them apart, such as the perforations. For example, you may have several stamps in the same series, that look the same, but one has 13 perforations, and the other has 12.