These little glasses are pretty cool. They are very futuristic, it appears to be a glass within a glass to site. These are made for espresso shots,yet I feel they can be used with alcohol as well. It also would be cool to use it as a mini bear mug haha.
Over all they seems pretty durable ..i am concerned with the durability slightly as they are not heavy nor thick glass.
Also they are quite small. I was expecting something a little larger before I opened the box. I do love the look and the asthetic as it is very classy. 
I will definate purchase more, hey i might even have a minature beer party with friends.