Huada Double Wall Insulated Glass Espresso Cup, 10 oz

This little mug is pretty nice but seems kinda delicate. I am not really sold on it honestly but the double hull is quite nice. It feels like it's going to break everytime I use it. Not sure if it's me or the mug. Overall it's a fine little espresso glass. 

http://www.amazon.com/gp/product/B01G0GCTKQ