Crocs comfort Level 1. Let their feet get a cool and comfortable feel in the Classic Clog from Crocs Kids. Synthetic upper. Clogs constructed from Croslite material for lightweight comfort. Synthetic lining and insole. Advanced toe-box ventilation system. Circulation nubs on footbed stimulate blood flow. Footbed conforms to foot creating a custom fit. Slip-on with back strap that can be moved to the front to wear as a clog. Treaded outsole for traction.