adidas Mens TechFit PowerWeb Base Layer Sleeveless Vest 100% Nylon Base layer sleeveless top designed with a compression fit to improve posture and reduce muscle vibration Techfit focuses your muscles energy to generate maximum explosive power, acceleration and long-term endurance Breathable mesh panels on the sides and on the back for ventilation Reflective details for enhanced visibility in low light conditions Flat lock seams reduce friction and help to minimise chafing