4-Layer Supportive Mattress Our bedside bassinet mattress combines memory foam (gentle cushioning), upright cotton (enhanced airflow), firm hardboard (prevents sagging), and a waterproof cover (easy wipe-down). Designed to promote flat, safe sleep and reduce pressure on your baby s back. Gentle Horizontal Rocking & Quiet Wheels Push the bassinet horizontally (not arc-shaped) to soothe your baby safely. 4 rubber wheels (each with individual locks) protect floors and roll quietly. Tip: Unlock all wheels when moving, lock when stationary. Convertible Bedside Sleeper & Standalone Crib 3-in-1 baby bassinet can easily switch between standalone crib and bedside co-sleeper modes.