You need to have or get your vehicle specific Ridgeline or Sightline clips x 2 pair and a pair of Yakima crossbars to complete the system.  Locks are optional, but suggested.  

You can find your vehicle specific clip and bar needs at Fitlookup.yakima.com  You can purchase clips at your local retailer or on ebay etc.  The Ridgeline tower has been superceded by the Sightline tower.  When you look up your fit, know Sighline clips will work with the Ridgeline towers as they are compatible. As mentioned you will need to go to Fitlookup.com or Yakima.com to see which Clips and Bars you need.  

These towers fit most all vehicles with a raised, flush rail on the roof of the car.  Double check any notes about sunroof/moonroof interference or limitations.  

Due to the extremely low price these are non-returnable.   Check out ratings and order with confidence.