This is a Plate Block of 6 Air Mail Stamps, they have never been hinged (NH), and still have the original gum (OG), they are very finely centered. Scotts #C7 Air Mail
They are a dark blue in color, take a look at these you will see how nice they are.
Date: 1926-27, Grade: VF+\, NH\, OG, Mint Mark: none, Color: Dark Blue
