Dobinsons 4x4 offers these Universal Aluminum Mounting Channels to act as cross bars across your existing roof rack in order to facilitate the installation of a Dobinsons 4x4 Roof Top Tent (RTT) or a Dobinsons 4x4 Roll Out Awning. They could also be used to carry a kayak, bike rack, ski or snowboard cargo box, or for a luggage bag for family vacations. They are sold as pairs. Lightweight and durable, these could be used for a variety of purposes, and also for other brands of Roof Top Tents or Awnings. Many new vehicles come with factory-installed load bars (running front to back of a vehicle), but no cross bars. These are your solution to make better functional use of your roof. NOTE: They do not come with the awning L-brackets, those are supplied with the Dobinsons awnings. Note: Photo is for illustration purposes only.