These are typically for heavy H drums. They're 23 and 3/4 inch inside diameter from rim to rim. They have 5/8 in bolts with heavy locking rings. Also 2 in and 3/4-in npt removable caps. I have some smaller ones without caps that are lever lock. they are 22.5 inches NEW 45.00 w/ latch lever lock ring. USED 35.00. Latch Ring only 15.00