Material:PU Leather,tested to be safe for baby. Size 11: Recommended Age 0-6 Months, sole Length 4.52′, sole width 1.77′. Size 12: Recommended Age 6-12 Months, sole Length 4.92′, sole width 1.96′. Size 13: Recommended Age 12-18 Months, sole Length 5.31′, sole width 1.96′. NOTE: For size, please measure baby’s feet to match the shoes sole length, the age is just for reference. Because of the different measurement methods, there may be 1-3cm of the allowable range error. Besides there might be slight color deviation due to different displays.