Our Infrared Technology Lightweight Thin Liner sock is perfect for when you want the comfort and performance of a sock, without cushioning. Offering a low-profile look with a barely there feel. Features seamless toe for comfort with reinforced heel and toe for added durability. Plus, TRUEENERGY® socks use yarn infused with NASA-inspired infrared technology. Infrared ceramic crystals are ground and permanently infused into the polymer yarn used. When combined with your body's natural heat it forms infrared energy to improve circulation and tissue regeneration promoting recovery and performance.