Need to vehiclery more than one kayak or canoe next time you go paddling? Look no further. Rhino-Rack has designed an extension piece that attaches to one of our current kayak and canoe vehicleriers (S512) that will allow you to add an extra watercraft. Have 2x S512 and 2x extension pieces and if your roof rack cross bar is long enough, you can have up to 4 kayaks or canoes mounted on your vehicle's roof!