Never used. Blue. Men’s 8-10 Women’s 10-12 Product details Made with injection molded, non-water logging EVA foam that enhances buoyancy and repels water, Aqua Sphere Alpha Fins provide a soft, comfortable fit and a buoyancy factor that enables a swimmer to maintain a higher body position in the water for a more efficient swim workout. ergonomic design includes specific right and left fins with full arch supports water channels provide stability and promote ultimate power transfer available in multiple sizes for women and men with larger widths should size up one size Provides isolated leg workout Made of non-waterlogging, EVA foam