Keep Mattress Secure: The metal retainer bars effectively prevent mattress movement on any bed frame type, featuring an L-shaped design with reinforced mounting plates that ensure your mattress stays perfectly positioned during sleep Universal Compatibility: Engineered with proper size to accommodate various mattress thicknesses, these retainer bars work perfectly across standard beds, adjustable frames, and RV mattresses for maximum versatility Anti-Rust Robust Metal: Made of quality metal with a specialized black coating that resists rust and corrosion, these mattress holders provide exceptional reliability and maintain their pristine appearance even in varying environmental conditions Complete Professional Kit: This set includes 4 heavy-duty metal retainer bars, 28 mounting screws, and 8 pieces of double-sided adhesive tape, providing everything needed for a secure and professional installation on any bed frame Flexible to Install: This versatile kit comes complete with screws and double-sided adhesive tape, allowing for secure installation on wooden slats or metal frames while protecting your bed frame from any potential damage