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 11/16″ or 6,7 cm wide and the inside is approx. Ø 1 3/4″ or 4,5 cm wide. Used item, signs of use.