This item contains two parts, one glass cup and one ice box. The material of the ice box is silicone. Firstly, place the silicone mold on the cup. Secondly, pour water into the cup to 'Fill Line' through the silicone mold. Finally, store in the refrigerator for four hours or until ready to use. Take out the silicone mold and use it. These glasses are made to preserve ice much longer than traditional cubes. Can custom logo and company name.