These mugs have two layers of lightweight borosilicate glass that are mouth-blown together to create a unique glass-in-glass effect. The result is a vacuum layer of thermal insulation that keeps hot drinks hot and easy to handle, and cold drinks cold without wet condensation.
The best coffee Mugs i have!
Keeps that important drink of the day toasty- looks loverly , practical size and proportion for a strong americano or herbal tea at night. Charncey. Malvern, GB. Sun May 04 2025