The 2XU MEN'S COMP TRI SINGLET utilizes a chlorine resistant lycra fiber called SBR Skin-X tohelp keep your garment fitting like new for longer. With excellent stretch and recovery property, the fabric in this garment works with your body movement whileretaining its shape. The polyamide yarn enhances moisture management capability as you transition from one sport to the next. Another fabric used is the Sensor Mesh-X which is nylon lycra fiber with high filament hydrophobic nylon yarn and optimal airflow engineering, sensor mesh-x represents the ultimate in moisture management. This garment is abrasion resistant and built to last through demands of swim/bike/run while still giving you unparalleled comfort.