Product overview Prevents mattress shifting on metal bed frames for a more stable and comfortable sleep surface. Compact blocking surface measures about 3.15 x 2.95 inches. Adjustable clamping thickness clamps bed frame rails from about 0.3 inches to 1.38 inches, compatible with most metal bed frames. Key benefits Reduces mattress movement so sleepers who move frequently are less likely to wake up to a shifted mattress. Simple mechanical solution that removes the need for daily readjustment. Durable construction resists deformation and corrosion for reliable, longterm use. What you get and ease of installation Package includes 6 mattress retainers, 12 flat head screws, and 1 hexagonal wrench. Parts are ready to assemble by hand; tighten and remove quickly with the supplied wrench. No special tools required and installation can be completed in minutes. Materials and performance Made from thickened metal with a protective coating for improved strength and wear resistance. Designed to bear pressure without bending and to maintain grip under regular use. Coating helps reduce surface wear and extends service life. Use scenarios For restless sleepers who need their mattress to stay in place throughout the night. For guest rooms and dormitories where mattresses are frequently moved or adjusted. For metal platform or railstyle bed frames that require a compact, adjustable stopper to keep the mattress aligned. Compatibility and sizing notes Blocking surface approximately 3.15 x 2.95 inches. Clamping thickness adjustable from about 0.3 inches to 1.38 inches. Intended for use with most metal bed frames; confirm your rail thickness falls within the adjustable range before installation. Practical details Simple, toolsupplied installation for quick setup and removal. Corrosionresistant coating and reinforced metal construction for dependable daily use. Sold as a set of six retainers to cover multiple sides or multiple beds as needed.