This is a marked Hendryx milk glass bird cage seed cup. The cup measures 3 inches long. There is a tab on the back of the cup to fit between the bars of the cage. The tab measures 3/4 inches wide and is 3/4 inch long. There is a large chip at the top back of the cup that does not interfere with use and it also is not obvious from the front. Price is reduced to reflect this flaw.