an excellent choice for allergy sufferers and children filled with soft polyester encased in breathable cotton percale quilted to keep the filling evenly distributed elastic straps stretch to accommodate a mattress depth of up to 34cm once you've discovered mattress toppers, you'll never go back to sleeping without one. an excellent choice for allergy sufferers and children, this design is filled with soft polyester and encased in breathable cotton. it's quilted with diamond stitches, so the filling will stay perfectly plump and evenly distributed, for a lump-free sleep every night.