Features Product data Material Form Colors F2 roof boxes are manufactured in glass fiber. That makes F2 light-weight, nonbending and steady. Glass fiber endures sunshine, tough weather and is very easy to maintain. We have succeeded with our design, and thus, F2 features very good aerodynamics. The round form maximizes loading capacity at the same time the air resistance is minimized. Many of our customers have earlier had problems opening their car's tailgate as that often used to hit the roof box. For such customers, F2 has provided a solution. Detailed product information. © Fiber-Form   design notes