For thick mattresses 12-13 inches and above, and recessed beds/mattresses that sit very deep, You must order the size (Extra tall) Regular or Long. ✅【Compatibility & Universal Fit for most bed types & sizes】: TotCraft Bed safety Rail Guard works with slatted beds, box springs or wooden base beds. Also suitable for Cribs, Queen beds, Double twins, king size beds, Single mattresses, Toddler beds, Tempurpedic beds, Bunk beds, full size beds, Twin beds, Double mattress, and Twin mattress. ✅ 【Life Time Warranty】: Don’t hesitate to invest in your little ones safety! Most cheap products last few weeks. We offer LifeTime warranty so buy with confidence! ✅►Safety First◄: The metal rods and mesh fabric are made of non toxic materials. ✅【Easy installation &Machine washable】: Very easy installation as illustrated in the instructional video and the manual. Also the mesh fabric is machine washable.