For your French oil lamp! If your lamp is only equipped with a chimney and you want to add a shade to your oil lamp then this is what you need. This slides over your burner. The outside is approx. Ø 2 27/32″ or 6,9 cm wide and the inside is approx. Ø 2 3/32″ or 5,3 cm wide. Used item, signs of use.