Here's a better description from the Great Planes Viper at Tower hobbies:

Wings: One-piece foam core with carbon fiber reinforcement, balsa
sheeting applied with epoxy for added security and stiffness,
recessed wing hold down bolts to minimize drag, center section
wrapped in double layer of fiberglass cloth.
Covering: Covered in Top Flite Monokote covering, color scheme is
entirely white.