My son had a horrendous flat spot on the back of his head at 3months. So bad that it dented in (see left side of picture). I didn’t want to have to get a helmet so I found this support pillow and ommmmg it is a lifesaver! 2 weeks into using and his flat spot is almost gone! We use it while he sleeps in his crib, and when he lays on the floor playing on his mat. Seriously if you have concerns about a flat spot on the back of the head, get this! The quality is amazing and it’s washable!

Before starting and after 2 weeks of use: