YMX BOXING® Ultimate Reflex Ball Set with Counter App - Great for Reflex, Timing, Accuracy, Focus & Coordination Training for Boxing, MMA and Krav Mega

Bought this instead of the other highly recommended name brand that is out there. It did not disappoint. I had my three adult children playing with it at the end of Christmas Day, and building up quite a sweat. I was surprised how much they enjoyed it and how long they played with it! All of them agreed it was the best under $20 gift and I should definitely keep it around. My son, the exercise fanatic, said he would be using it downstairs in our gym area as an additional form of exercise. Thanks to the lengthy elastic included, you can adjust for anyone. The only thing I would suggest is that four headbands instead of two, so that four people could play with all of the balls at one time but it is well worth the money spent!