Many vintage Boston Whalers have a fuel tank flange that is not threaded. The fuel senders were mounted using nuts and sleeved bolts. This fastener kit includes (4) 1/4"-28 x 7/8” socket head cap bolts and (4) 1/4"-28 nyloc nuts, with all parts being high-quality Stainless Steel. A 3/16” hex drive is needed.