Lenz Heat Socks 5.1 Slim FitThe heat sock 5. 0 toe cap slim fit knee socks are ideal for narrow feet and legs. They are ergonomically knitted for an optimal fit and the ring bandage offers pleasant support on the foot. Shin protectors as well as further reinforcements at toe and heel prevent pressure points. The skin friendly material mix of merino wool and silk is breathable, fast drying and comfortable to wear. The lightweight rechargeable lithium pack battery is optional and