US 9-10yrs EU 134/140 Perfect for young riders, this light equestrian shirt will keep them cool during training or barn work with soft, stretchy performance fabric. Mesh Detail Under Sleeves: An added level of breathability, the under sleeves are made of a lightweight mesh for improved airflow and cooling power. Contrasting Color at the Collar: The cute equestrian style is accented by a contrasting color at the collar, which can be zipped up or down according to preference and comfort.