The darkened plastic looks really nice, and the four dot system is a good way to make sure you hit your hydration goals for the day. You naturally count your bottles as you twist the cap back on. Very clever, and very affordable. Would pay premium for a glass/metal thermace version..
Honestly is a very cool item and a very simple and smart idea. My only complain it would be that the material is plastic and I think for me it would be better if it was made on glass and if he has like something to have a better grip on the bottle and an easy open cap.