If you have a Rhino-Rack Vortex or Heavy Duty Crossbar system and want to mount a number of Rhino's kayak and canoe vehicleriers Includesding the S510, S512 or the Kayak Extension Piece S512X you will need the KC-FK8 fitting kit. This fitting kit will also suit the Thule Aero and Thule Aeroblade cross bars.
Installation Instructions