Worn 2 or 3 times, they also run small. I normally wear a US size 8.5, I find European sizes run small, and I usually wear a size 39 or 39.5, but I had to order these in a size 40 This is an authentic pair of LOUIS VUITTON Perforated Horizon Flat Sandals size 40 in Black. These stylish sandals are crafted of smooth calfskin leather in black, featuring the LV logo embellished throughout. They feature a leather ankle strap that buckles.