Made from borosilicate glass these cups are heat resistant and hard working. They come with silicone or cork grips to make them easy to handle. Being dishwasher and microwave safe they are easy to clean and reheat drinks (removing the lid and grip). Hot drinks keeping warm for around 30-90 minutes depending on your preferred drink. And don't think coffee drinkers have all the fun, there are tea infusers, so you can partake in your favourite loose-leaf tea too.