The heating pads have one adhesive side that you stick to the outside of your sock/stocking. They warm your feet for up to 6 hours. The Naha pads are activated by opening the packaging and letting the pads react with oxygen. The powder is non-poisonous, fireproof, environmentally friendly and biodegradable. The sachets can therefore be disposed of along with household waste. A pack contains two sachets, designed for onetime use.