Metal Charm Collection (メタルチャームコレクション) is a set of 26 charms released August 21, 2008 by Movic as two full complete boxes of 12+1.
The boxes both retail at 6,300円 ($84), making the charms 525円 ($7) each.
Second-hand, they can range from 50円 ($0.67) to 1000円 ($13.33) depending on the character.
The metal charms are pretty much what their title says. Each charm has a glossy front and metal back, as well as a small metal tag of sorts with Hetalia written on it. They feature an old set of Himaruya's art, with the pictures resized to keep each charm a similar height.
Unlike most item collections divided into multiple boxes, the metal charms have a noticeable difference to tell their sets apart; Box A charms have a gold-coloured back, while Box B charms have silver. The listed charms for Box A are Italy, Germany, Japan, Austria, Switzerland, China, Korea, Greece, Finland, Sweden, Hungary, and the white flag. The listed charms for Box B are Italy, England, France, America, Lithuania, Estonia, Latvia, Egypt, Spain, Poland, Russia, and once again, the white flag. Both boxes, in addition, have a bonus Romano charm, with different packaging.