This charcoal grey water tumbler is perfect for on the go travelling, for taking smoothies, herbal teas or any hot or cold refreshment the double walled design helps keep the exterior of this product a comfortable temperature to hold. The double walled, vacuum insulated body is made from stainless steel which insulates cold drinks for up to 24 hours & hot drinks for up to six hours, great for long commutes. The sturdy Tritan lid design easily slides open & closed for a practical one handed drinking.