Doomoo Supreme Sleep Large: Back PositionerDoomoo Supreme Sleep Large: Back Positioner The Doomoo Basics Back Positioner allows the baby to be placed comfortably on his back while preventing the risk of plagiocephaly ("flat head") linked to this position. Width: 60 cm It is a sloped positioner in viscoelastic memory foam with two side rolls that can be adjusted with velcro fastenings. The viscoelastic memory foam moulds itself perfectly to the newborn babys head without exerting any pressure