Belmor VL-881-1 Smoke Ventvisor Side Window Deflector for 2002-2017 Western Star 4900EX Low Max Lets fresh air in and stale air, odors, and heat out  while keeping the elements at bay and reducing interior fogging Deflects water away from the drivers line of vision to side mirrors Helps keep the driver comfortable and alert Installs easily with 3M automotive grade tape Made in USA and backed by a Limited Lifetime Warranty