Both side skirts also are designed for exceptional strength and performance. The USS-120 and USS-160 are created with UV-protected one-piece fiberglass-reinforced plastic and mounting to the support leg wingplate. Both devices also are California Air Resources Board-compliant for California operation; the USS-120 as a standalone device is CARB-compliant for refrigerated trailers only.
The USS-120 is SmartWay-verified to achieve greater than 4 percent fuel savings, and the USS-160 is SmartWay-verified to achieve greater than 5 percent fuel savings; actual fuel economy gains may vary for both designs. Additionally, EPA SmartWay has classified the USS-160 as an advanced side skirt, which allows truckers to use them without any other aerodynamic device on dry vans.