I'm 165cm (5'5); normally buy size 36 (US 4) or S. I got the S here. About the buttons: they don’t look cheap to me​,​ but it is still plastic ;) ＜abbr＞Sezane​,​4​,​$225​,​5'5-5'6 5'5-5'6​,​Blazer​,​Coats​/​Jackets​,​French Brands​,​Size 4 All Reviews​,​Jackets​,​Sezane＜​/​abbr＞