The only difference between the half height and full height options are strictly in regards to the height of the wind fairing on the front of the roof rack. Most other companies define this as having a "light bar cut out", but we make ours a little different. Our rack uses a shorter fairing to leave room for a single row light bar without limiting you to the size of light bar you can install. If you are not planning to install a light bar on your roof rack then you would want to select the "full height" option. Other than the space for the light bar, the racks are completely the same. Fairings can also be purchased separately down the road if you change your mind!