CROSS-BACK VENTILATION AND MOBILITY. The Nike Pro Tank helps keep you cool and dry during intense training or competition. Elastic straps cross in the back for breathability and a stay-put fit that moves with your body. Sweat-wicking comfort: Dri-FIT technology helps you stay dry, comfortable and focused. Breathability in motion: cross-back design lets your skin breathe when the action heats up. Elastic straps flex with your body to promote natural movement. Extended coverage: hem is longer in the back to give you coverage as you bend and stretch.