Xmistuo Slip On Slide Low Heel Boho Butterfly Nonslip Sandals Sz 8.5/9 In the Chinese shoe sizing system (often utilized for this brand, Xmistuo), the number 250 specifies a foot length of 250 millimeters (or 25 centimeters). [1] (https://www.ebay.com/itm/326937582552)This roughly translates to the following standard international sizes:US Women's: 8.5 – 9EU/European: 39 – 40UK Women's: 6 – 6.5