Reliable, comfortable, lightweight and durable - the F-121 is the choice for the triathlete and meets high demands! The upper part of the shoe is barefoot-friendly and crafted from a mix of lightweight open-air mesh. Providing the shoes with ultimate ventilation and stretch-free synthetic upper to create shape, spread pressure, stabilization to the foot and provides an anchor point for the straps.Tri-specific 2-strap closure sports an open tongue for ventilation and large heel pull for easy entry and faster shoe changes in transitions.Upper: barefoot friendly, and extremely ventilated Tri-Specific with open tongue,Fastener: Tri-Specific 2-strap closure,Footbed: breathable and removable,Cleat Compatibility: compatible with C-20, C-30 cleats and all 3-bolt clipless pedal systems,Vented tongue for breathability,Easy taken off with rear loop-hook.Sole Technology:Lightweight, injection fiberglass reinforced sole delivers a stiff, powerful and efficient pedal stroke. Vent port at the front for effective cooling to your feet. Sole i equipped with two non-slip treads for safe walking.