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 4 3/16″ or 10,5 cm wide and the inside is approx. Ø 2 3/4″ or 6,8 cm wide. Used item, signs of use.