For your consideration is a vintage recessed ceiling ‘can’ light with round glass shade / diffuser marked LANCASTER 3875. The part of the shade that is seen is approximately 4 3/4 inches diameter and extends down below the mounting flange about 1 /8 inch. Diameter with mounting lip is 5 3/8 inches. The shade is white glass or maybe ‘clam broth’ and is somewhat translucent. It is in excellent condition with no chips or damage. The outside diameter of the mounting flange is 8 1/4 inches. PLEASE NOTE that one of the (four) adjustable mounting brackets is missing (not used in the original installation). This is a nice vintage item that you are purchasing as-is and as-pictured. Thank you for your interest.