This is an unworn quarter zip polo from Horseware Ireland. It is their Oria New Technical Polo in a white moisture wicking fabric with tiny holes for breathing.
The shirt is a size 6 and some measurements follow to help with fit.
armpit to armpit laid flat is 16 inches
the sleeves are short
the back length is 24 inches
The shirt has its original tags and is in good condition. Its original retail price was $39.95