I have two 1 1/2 inch thru-hull fittings including the retaining nuts. They are Apollo by Conbraco brand. One was installed for demonstration purposes then removed, the other was never installed. Neither have seen water. Defender has these on sale right now for $38. each. You can buy these two for $45. plus shipping, ($12.35 to the lower 48) so your total cost for two will be $57.35. I will take paypal. Thanks!