Built with plywood. Precision saw cuts for tightest fit to quarter round and square walls. Needle-sharp, rust-resistant nails spaced for handling and strong enough to withstand a full power stretch. "C" Pin only for plywood, particle board or hardwood floors. Ringshank nails polished for visibility and prestarted to assure a straight drive. "C" Pin only for concrete floors prestarted with hardy tempered nails to penetrate without splitting concrete and to ensure a solid anchor.