Golden Eagle 30308 6/CS 303® Aerospace Protectant. Originally engineered for aerospace and aviation applications, 303® Aerospace Protectant has found its way into millions of homes for day-to-day use on vehicles, sports equipment, patio furniture accessories and more. Unlike many protectants that leave greasy residues, Aerospace Protectant dries to a clear matte finish. And because it’s water-based, this protectant is safe to use on all products, from your vehicle’s paint job and leather seats to internal engine parts.