Huggaroo's orthopedic knee pillow is designed to help adults who prefer to sleep on their side and suffer from low back pain, sciatica, hip pain or knee pain. It is made of premium, firm, high density memory foam, which will not go flat with use. The plush blue or grey cover is easy to remove and machine-washable. Our knee pillow’s ergonomic biconcave shape fits perfectly and comfortably between your thighs or calves and improves your spine, hip, and leg alignment while you are sleeping on your side. This can help alleviate back, sciatic nerve, and leg pain.