Double Wall Glass Set of 2 double-walled clear glass cups. Heat is not easily transferred, so even if you put hot drinks in them, they won't be too hot to hold. Also, heat is not easily lost, so both hot and cold drinks will stay at their temperature for longer. Ice also melts more slowly. Diameter approx. 6 cm Height approx. 6.5 cm There is a manufacturing scratch on the inside of one of the glasses. Thank you for looking.