Undershirt using HEATTECH technology, size 150, black. I received this as a gift, but my child tends to get hot easily and won't use it, so I'm selling it. New, unused - Brand: UNIQLO - Model Name: HEATTECH - Color: Black - Size: 150 - Material: 53% cotton, 42% acrylic, 5% polyurethane Thank you for looking.