The Tag is Manufacturer's size that display on the product, please kindly refer to the size instruction we offer. You can use the US size and the waist circumference to check. US-S (Tag M) : Waist:26"-30"(68.0cm-78.0cm) US-M (Tag L) : Waist:30"-34"(78.0cm-86.0cm) US-L (Tag XL) : Waist:34"-37"(86.0cm-94.0cm) US-XL (Tag XXL) : Waist:37"-40"(94.0cm-100.0cm) US-XXL (Tag XXXL) : Waist:41"-44"(100.0cm-104.0cm)