Secure your outdoor decorations with these windproof screw hooks featuring security buckle design for maximum protection. Features: security Buckle Design: Prevents hanging items from falling even in strong winds, offering superior weather protection compared to ordinary hooks for outdoor string lights and decorations. Sturdy and Durable: Made of black rust-resistant carbon steel, suitable for indoor and outdoor use. Each hook supports up to 40 lbs for long-lasting performance. Easy Installation: You can screw the hooks into the wood by hand or with a wrench, or use an electric drill to drill a 0.24 inch hole in the concrete wall, plug the expansion tube into it, finally use a wrench to screw the hook in. Wide Application: Ideal for hanging outdoor light strings, patio lights, Christmas decorations, plants, wind chimes, bird feeders, flower baskets, and various outdoor decorative items on terraces, roofs, ceilings, porches, and fences. Specifications: Material: Carbon Steel Color: Black Installation Type: Ceiling Mount Size(LxW): S : Screw Hook: 5.23 x 2.6 cm Expansion Tube: 2.8 x 0.5 cm L: Screw Hook: 5.53 x 3 cm Expansion Tube: 2.8 x 0.5 cm Package Contents: 20 x Screw Hooks 20 x Expansion Tubes Please Note: Ensure proper installation using suitable tools and surfaces. Check weight limits before hanging heavy items.