The Tretorn Micro X Trainer is a pressureless tennis ball that uses micro cellular technology. These balls have the best reputation for tennis ball machine use because they offer superior consistency and remarkable playability.
The Tretorn Micro X Trainers offers patented "micro cell" technology. While a conventional ball flattens on the strings allowing air to escape when struck, a Tretron ball has 700 million air-filled micro cells that do not allow air through the ball's rubber core; therefore, these balls will never go flat. Depending on the surface you use these on, you can get months or even years out of these before the felt will wear off the outside.
The bulk bucket is perfect for coaches, clubs, schools and ball machine owners.
Pressureless balls are a better option for ball machines because they have the same bounce and feel which can allow you to achieve consistency from the shots fired.