Moisture is wicked away from feet to promote warmth; Surround Heating Element envelopes the toes; The "Welded" wires allows for a seamless sock for a better fit with more comfort; Compression: gentle - PFI 30, 5 - 10 mmHg, promotes circulation and speeds recovery; Material: 49% polyamide, 26% wool (merino), 25% elastane; Heat socks Only