4 pack of glass mirror coasters, each backed with a 1/8 in thick rubber pad for protection/grip. Each coaster measures 4 square inches with a thickness of about 1/5 of an inch and weighing approx. 3.39 ounces each.. They serve as a multifuntional piece, in that you can house your glass, or take a look at yourself to make sure you're good to go.  Also worth noting, all of the edges and corners are beveled to reduce the risk of being cut; because I think it'd be cool if your blood stayed in*side* your body. That being said; handle these with care; like you would any other glasswear.