I bought this matching set of jersey and pants for my nine year old son. The Y24 fits him great with some room to grow. We do alot of desert trail riding in Nevada, and some days it can get really warm. I like having a vented kit and a regular kit for each rider in our family. The Troy Lee Air GP gear has been great for me, and I was so pleased that the youth versions have the same quality and features. My only complaint is that we got a pair of pants with a bad buckle. I'd like to return for a new pair but we are in the middle of our fall riding season and I don't want my kid to be without this set just yet!