When factory-installed on a LEER Model 100XQ, 100XL, 100XR, 100R, 180, or 122, the Thule Aero Bar and Tracker II Roof Rack systems have a maximum load capacity of 150 lbs. When factory-installed on a LEER Model 100RCC or 180CC, the Thule Professional Roof Rack system has a maximum load capacity of 400 lbs.