This travel mug set is made of silicon with stainless steel rim on the top. This silicone is edible and non-toxic, tasteless, mold free, sterile.The capacity is 270 ml (9oz). Before folding, the top is 3.8 inches in diameter and 3.3 inches in height. After folding, it is only 0.59 inch high and can withstand temperatures up to 200 degrees celsius. It is suitable for cold drinks, tea, coffee and other hot drinks.Good Promotional Gift.