So you are serious about sculpting your body and gaining more muscle mass? Thanks to the XLFLEX, you will be able to track your arm size as you lift. It connects to your smartphone and shows your measurements live. You will also be able to see your results on its display in front of a mirror.
The XLFLEX not only works on your arm but other body parts. You can use 2 or more units at a time. Expected to ship in June. More information is available here.