Easily attach your Thule Caprock roof platform to your factory rack or other third-party rack systems Fits crossbars between 0.76" / 1.9 cm and 1.9" / 4.75 cm in width and up to 3.3" / 8.4 cm wide Crossbar kit includes four mounting points for a secure attachment Locks are included to secure your roof platform to your vehicle's crossbars