Our Serene mugs have a 7.4-ounce capacity and are crafted from premium lead-free borosilicate glass and feature an innovative double-wall design, keeping your coffee luxuriously hot or your iced tea refreshingly cold. Plus, the outer wall remains comfortable to the touch - no more burnt fingers or messy condensation rings! This set of 2 is Dishwasher, microwave, oven, and freezer safe (up to 350 degree F).