UCBL is for children or Yonge adult who need a superior biomechanical control and support in their athletic or casual shoes. They are designed to correct the alignment of the foot and to prevent any future injuries. This orthotic is the best choice for children of 4 to 14 years of age. Best to use with:Lace-up or slip-on shoes Shell Density:2 mm, 3 mm Length:Sulcus, Full Patient:Accommodative / Corrective, good for children with flexible flat foot, Maximum biomechanical correction.