Review on ☕ Optimized Latte Double Walled Coffee Glasses by Matt Heringer

I bought the glasses because I was hoping the coffee would stay hotter longer than my current mug. It's relatively cheap (less than $20) for a set of 4. I tested the double wall glass against my current ceramic mug by filling it with boiling water. The temperature is 145°F (double wall) compared to 139°F (ceramic) after 15 minutes and 134°F compared to 128°F after 24 minutes. So it works - plus or minus the difference in volume of each (more on the cup means more heat capacity) and surface area (more on the cup means heat is lost faster). However, I would say that the glass quality and finish is mediocre. I quickly noticed that the edges of the lenses were misaligned. I think it has to do with how they are built. With the equalizer on my phone the difference is between 0 and 2.2 degrees (3.4 degrees on the picture includes about 1 degree of the countertop. Visually you can see how each glass is slightly different. Overall I think they mean Meet requirements, and don't cost enough to make me want to return them, not sure if swapping for new ones guarantees the next four are higher tier.