DD got one in the fall of 2009 when she started playing softball, initially to help with the overhand throw. After she wanted to pitch, it was useful in correcting the "arm curl" follow through. It got to the point that it was only used sparingly - 10-12 pitches per practice - because she like it too much and was becoming dependent upon it. She used it for maybe 3-4 weeks total, and now we don't even know where it is!