The Triboro Just Born Fresh Air Crib Liner - Gray is a breathable single layer mesh improves air flow and helps prevent suffocation. Full back panel coverage protects little arms and legs from entrapment injuries. Bounce back panels prevents climbing and potential injuries. See- through single layer mesh provides better visibility for peace of mind. Easy one time installation fits most full size cribs. It securely stays in place even during sheet changes and creates a beautiful and safe nursery environment for your bundle of joy!