These are custom specialty round 316 stainless steel u bolts supplied to our long time customer. They were manufactured domestically to the customer's drawing in plain 316 stainless steel material, with a lead time of 5 days. Material certs and a certificate of conformance was provided with the parts per the customer's request. The inside width is 4-9/16" while the inside length is maintained at 7-1/4". Approximately 3 inches of 1/2-13 thread was incorporated on each leg.