Kobayashi Pharmaceutical - Kiri-Gai Foot Warmer - Sock Type - Toe - 5 Pairs Per Pack Product Description\n\nSock-type adhesive warmer\n5 pairs per pack\nApprox. 3mm thick Made in Japan\nSticks firmly without slipping\n\nContinuous heat for 8 hours\nColor: Black\n\nShoe-specific warmer, adhesive type for socks\n●Maximum temperature: 43°C\n●Average temperature: 36°C\n ●Duration: 8 hours (measured for use inside shoes) (Measured using the Foot Warmer Standard Test Method of the Japan Foot Warmer M