Features of the Smartwool Men's Merino Sport 150 Hidden Pocket Tee Moisture management, temperature regulation, and odor resistance of merino with the durability and quick dry time of polyester Flatlock seam construction designed to minimize chafing Offset shoulder and side seams designed to increase comfort and minimize chafing while wearing a backpack Mesh in key Areas designed to increase breathability and comfort during strenuous activities Hidden secure pocket at side seam Fabric Details 56% Merino Wool, 44% Polyester