This is an unworn purple polo from Horze in their Junior Holly Polo Shirt, sized 9-10 years.  The shirt has a sleeve patch and silk screening on both the front and the back.  

The shirt is tagged as a size 9-10 years and some measurements follow to help with fit.

armpit to armpit laid flat is 14 inches
the sleeves are short
the back length is 20 inches

The shirt has its original tags and is in very good condition.  The original retail price was $30.