At first, I thought this was the popular retro remake version and unfortunately it no longer has a size/care label to clarify. However the 'Designed by Pony in conjunction with Bruce Oldfield' patch does seem to match the original, which is different on the retro versions I've seen.
Size: boy's/youth large. Armpit to armpit is approximately 16 inches.
Generally good used condition with minor signs of wear/light bobbling - please see photos.