Initial package received was empty! However, in good Amazon fashion they replace my order with over night delivery. Once received, only 5, of the 6 pair of socks actually fit. One pair was sewn incorrectly or something and had no elasticity. Very strange as I was not able to get it even half way on! Of the 5 pair that fit, they seemed large. I wear an 11.5 running shoe and the large size is for 9.5-11.5.