SNOWBIRD SKIS FOR.35 - .60 SIZE OR 48" (914 MM) - 72" (1830 MM) WINGSPANNo more seasonal flying! Du-Bro Snowbird Skis make it possible to fly all year. Easily mounts on airplanes with dural or wire landing gear in about 5 minutes. Snowbird Skis are manufactured out of high density polyethelene. Runn..