Summer Infant Symmetry Sleep Postioner: The Symmetry positioner is a scientific leap in infant positioning. With clinical trials backing its effectiveness and FDA endorsement recognizing its medical potential the Symmetry proves to be best of the best. The SIDS Back To Sleep campaign produced a side effect known as Positional Plagiocephaly or Flat Head Syndrome. The Symmetry is the answer in active prevention. Soft curves contour baby’s head and body while positioning them in comfort. The FloThru cover is breathable to help reduce overheating. A simple and effective reminder system lets parents position their baby correctly. Endorsed by its co-creator Dr. Hahn. Includes Symmetry Caliper to measure symmetry of baby’s head.