Foot warming packs N-Ferno® 6995. Contains 2 pcs. Self adhesive. Self-contained packs activate when exposed to air. To activate, just open the pack. All natural ingredients heat up when they contact oxygen. Foot style warms up to 6 hours. Provides warming to full foot and will fit in shoes or boots from size 41 and up. Can not be cut. Carton: 20 pcs.