Earth Energetic Fitness Shoe Womens Synthetic Midsole Material: EVA--Provides lightweight, flexible, cushioning that is highly impact-resistant. Lacing System: Traditional Lacing System--Traditional lacing system provides a tighter fit, for more centralized support. Heel Technology: Gelron2000--Precisely calculated and located in the heel cup. Softens shock and prevents impact from reaching the heel, leg or lower back. Classification: Cross-Training