Incorrect size chart or product not built to spec
"I ordered two mid-support and one max-support ankle sleeves in the same size - for 8. 75-9. 5 ankle circumference. The max-support was way bigger than the mid-support sleeve, the fit was loose, felt no compression at all. I called Customer Service who said that it may have just been a bad item, so they processed an exchange. When I mailed back the item, I even included a side-by-side photo of the mid-support and max-support sleeves to show the disparity. Got the replacement and it was still bigger. I haven't had sizing issues with CEP products I've bought in the past - socks, shorts, pants, knee sleeves, etc. But either the sizing guide for this max-support ankle sleeve is wrong, or production is messed up and it runs big."
