1 3/8" tall. The phrase "knock on wood" is believed to have come from an 18th-century children's game in which touching a piece of wood would protect you from being tagged. The notion traveled into the following century, and during the first World War, British troops would carry these tiny wooden charms into battle. They hoped the lucky material would protect them - as it did during their childhood - from getting tagged. (Forever). WWI era so-called "Fumsup" charms like these were made and sold cheaply in the thousands. Silver colored body, hand-painted wood face. The arms are hinged so they move up and down.