The protective sole was designed by Swiss engineers from Laurastar. It protects delicate materials and prevents shiny spots on dark fabrics. Additionally, it allows for ironing heat-sensitive fabrics like silk. This is made possible by a special coating that reduces the heat from the iron's soleplate. The protective sole can be easily attached to your Laurastar Smart I iron. First, place the tip of the iron in the front part of the protective sole, then lower the iron to secure it using the designated tab at the back of the sole. Wait about 2 minutes for the sole to reach the right temperature to gently iron delicate fabrics.