1460 Heated Flat Footbed Heat Factory's patented Flat Footbed is easy to use - one size fits most! The cavity under the toes is designed to hold Heat Factory Footwarmers. Specially designed air channels on the bottom of the footbed increase air flow to the Footwarmer creating plenty of heat to keep those feet warm on cold days. The Footbed features a brushed nylon top with antimicrobial & antifungal additives. Sold in men's or ladies sizes trims on the heel. Footbeds include one pair of Heat Factory Footwarmers(1948).