The Dr. K Chiro-Core Side Sleeper is an amazing ergonomic pillow and our exclusive invention. The curve of the pillow fits your body perfectly. Side Sleepers hug the lower half of the pillow while their head is cradled by the top half. The pillow is especially effective If you start sleeping on your side and then later roll on your back. The pillow stays perfectly positioned throughout the night no matter what position you move to. Our patent pending fill is the perfect mix of pliability and firmness.