Furuno RG-12/U Type D Vintage Marine Boat Coupler Unit. Vintage Type D Coupler Unit. This unit is in very good physical condition and appears to have never been installed. This listing is only for what is shown in the photos. No other parts or pieces are included.We Now Accept Credit Cards! The item "Furuno RG-12/U Type D Vintage Marine Boat Coupler Unit" is in sale since Thursday, March 03, 2016. This item is in the category "eBay Motors\Parts & Accessories\Boat Parts\Other". The seller is "buckaroobonzi" and is located in Costa Mesa, California. This item can be shipped worldwide.