HEIGHT 10.5CM, NO PRESSURE ON THE ARM: The arm can be easily placed on the bottom, and the arm will not be pressed when sleeping on the stomach, allowing the blood to circulate naturally. SLOW REBOUND SPACE MEMORY FOAM: Moderately soft and hard, full of elasticity, giving soft and comfortable support to the face. ERGONOMIC DESIGN: Elevate the head to avoid excessive bending of the neck. Effectively avoid the physiological bending of the spine, the muscles of the neck and waist, soreness and fatigue, and the blood in the arm that causes soreness and numbness. SHELL PROTECTION DESIGN: Make it easier to carry and store, and protect the inner core, not easy to get dirty. DURABLE MATERIAL: The shell is made of high quality plastic material, which is waterproof, durable and easy to clean. Light enough to carry around.