A useful extension to the blackroll booster, the price is about right. The product is not as revolutionary as the makers believe it to be but it does help target points which are not too deep, eg on calf or back. I found it difficult to work trigger points deep in my thigh and hamstrings. I would recommend using one of the (cheaper) blackroll balls for this.
Easy to charge & use
Not overly effective
Feels like most of the vibration ends up going into your hands