These bamboo/silicone mug can be used for cold or hot beverages. They are made of bamboo fibres and temperature resistant silicone. They are incredibly durable and 100% dishwasher safe — a lightweight alternative to stainless steel mugs or larger, clunky to-go mugs. It is easy to carry in a purse or smaller bag. They can last for many years if taken care of properly taken care of properly.