Size: 39- US 8 Rubber sole Elastic Upper：Stretch breathable ultra light weight lycra material give excellent flexible and comfortable make you feel like Wearing socks. Non-Slip Out Sole: Durable rubber sole, specially designed sole pattern can effectively increase friction, provide excellent grip in slippery conditions, and prevent slippage during exercise Drain Hole Design：Unique and top-quality sole with holes on each bottom to drain the water for fast draining and cross ventilation