Function: breathable, comfortableSize 7-9.5 is US size, size 39-44 is EUR size.US 7=EUR 39=245 mm, US 7.5 =EUR 40=250 mmUS 8=EUR 41=255 mm, US 8.5=EUR 42=260 mm US 9=EUR 43=265 mm, US 9.5=EUR 44=270 mm