Quickie style replacement sling seat. Slotted 4 hole pattern: 1", 4 1/2", 3 3/4", 4 3/4". Six sizes available: 15"wide x 16"deep, 16"wide x 16"deep, 17"wide x 16"deep, 18"wide x 16"deep, 19"wide x 16"deep, and 20"wide x 16"deep. Rails are not included. Sold as each.