The Swarovski Drop Hot Fix Cabochon Flatback 2308/4 offers the look of a pearl with a crystal core and a flat back. It is available in 3 sizes in a limited range of pearl like colors. This Swarovski Flatback is made of "Advanced Crystal" and is lead free. It has a heat activated glue already applied to the back of the stone for easy and strong hot fix application to fabrics.