Host Freeze Beer Glasses, Frozen Beer Mugs, Freezable Pint Glass Set, Insulated Beer Glass to Keep Your Drinks Cold, Double Walled Insulated, 16oz, Grey
It took a year of trial and error to perfect the exact "ultrasonic welding" geometry that joins the clear plastic parts together and allows this cup to mimic the elegant shape of a pint glass. The plastic had to be engineered to handle expansion and contraction from the gel freezing as well as extreme cold and warm conditions.