I'm afraid that you regard the size as Euro Size and US Size.please do not follow system size chart !!!
<br />  if you want make a very correct choice you should choose by the size chart at the Second image !!!
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<br />>available: XS,S, M, L, XL,XXL
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<br />>ASIA SIZE Shoulder / Chest/ Length / Sleeve
<br />   XS:37cm/43cm/63cm/16cm
<br />S:38cm/45cm/65cm/17cm
<br />M:39cm/47cm/67cm/18cm
<br />L:40cm/49cm/69cm/19cm
<br />XL:41cm/51cm/70cm/20cm
<br />XXL:42cm/53cm/73cm/21cm