The Thule Xadapt 3 – Adapter Kit are 80mm carriage bolts used to replace the 50mm and 60mm bolts included with certain Thule water sport racks. The 80mm are needed for vehicles with larger than usual cross bars. Thule Xadapt3 Adapter Kit 3 converts your Thule Hull-a-port Kayak Accessory to fit the oversize crossbars of a Nissan Xterra, Nissan Frontier or a Thule Xsporter Truck Rack. One Xadapt kit converts one Thule Hull-a-port.