From Crocs, the Women's Classic Ballet Clogs feature: Innovative Croslite™ upper, which now contains 25% bio-circular materials like cooking oil from other industries Lightweight, water-friendly and buoyant Slimmer, classic ballerina design Ventilation system that allows air and water to pass through multiple ports inside of shoe Slip on design Pivoting heel strap for a more secure fit EVA outsole Imported.