I love this product! I can exercise my dog for an hour throwing balls in the field and not wear myself out! The only complaint I have is it is a bit bulky to carry on my walk to the park, maybe a folding or collapsible model?  But other than that It has held up to cold weather ( 10 degrees) , many drops onto concrete and daily use for the past two months.  I use it with the rubberized balls, they seem to last longer and I get better distance than the "tennis" type balls.