Snowbird Main Skis, Lime Green: .20 to .60 Dubro Snowbird Skis are manufactured out of high density polyethelene. Runners are molded right on the ski for better tracking. Ideal for up to .60 powered aircraft. Featuring a spring loaded design, our Snowbird Skis flex on take-offs and landings yet remain in a positive lock position while in the air.All mounting hardware included. 2 Skis/pkg.