Per Una longline cardigan with stripes size US8 (UK12)

this is a lovely longline cardigan with black and tan stripes with accents of orange and golden yellow. no buttons, open front cardigan, bought at Marks & Spencer in Europe. angora, acrylic, cotton blend. excellent condition ! even though this says it's a size UK 12 I think that it runs small and fits like a US size small, which is what I was when I bought it :) measurements: pit to pit 18" shoulder to bottom hem: 30" under arm sleeve length: 17"