What is the good luck charm that Norman Bowler carries?

Norman Bowler, a character from the British sitcom "Keeping Up Appearances," carries a small, silver horseshoe as his good luck charm.

He often refers to it as his "lucky charm" and believes it brings him good fortune. It's a running gag in the series, with other characters often poking fun at his superstition and the perceived lack of effectiveness of the horseshoe.