The one I am asking about is the signal on the left. It is 3 1/4" wide, and 3 3/4" tall. It is dry press porcelain. It may be a U-267A. That one shows a listing for a dry press piece in gray. The comparison insulator on the right is a sim U 241B made by Pittsburg High Voltage. Let me know what you think the piece on the left really is. Thanks. By the way, this was a recent 'free table' find. Confirmed at a U-269B. Thanks Elton and others.