Keep Your Hands Warm with Winter with Our Reusable Round Heat Pack. Supplied with Metal Plate for Activating. to Reuse, Heat Water in Container with the Patch Inside Until the Inside Gel Returns to Its Liquid State & Press the Metal Plate Back into Place. Great for University Students & Professionals on Their Daily Commute. Colours: Clear Transparent, Red, Green, Yellow, Pink, Blue. Minimum Quantity: 500.