Derila Ergo Memory Foam Pillow works by using orthopedic contouring and viscoelastic memory foam to keep your spine in a neutral position. Unlike standard pillows that can flatten or push your head at an awkward angle, its “butterfly” shape creates specific zones that adapt to your body as you move.The Neck Cradle: A central groove supports the natural curve of your neck (cervical lordosis), preventing the head from tilting too far forward or back.