1. The outside of the cup showed ripple.
2. Compared with the common cup there are two tier outside more protect, that is better to heat preservation and heat insulation, it will keep the coffee which in the cup more time, and also it will not feel very hot when you hold the hot coffeer.
3. We have existing specs: 4OZ. 8OZ. 12OZ. 16OZ. 20OZ