By Superfeet Style: Carbon fit Size C Description- Size C= Women's (6.5-8) Men's (5.5-7)Kids Size 6This means for womens 8.5 Footwear a size 8 insole would be needed- and for a men's 7.5 Footwear a size 7 would be needed. Please refer to the measurement photo and look at their website for size info to get a better understanding of the size you should choose.My info is based on my experience only and you will need to verify with the site or measurement photo above. Color code: Letter E (this letter is not for sizing)Carbon fit fits similar to an orthopedic insole. Features: •Biomechanical Shape •Low heel cup•Evolyte™ Carbon Fiber •Ultralight density foam•Beveled edge Fits best for: Wide range which includes - tight fitting shoes -runners, athletic or regular shoes that have low volume width-narrow footwear -footwear that needs extra thin insoles -people looking to get a dupe version of orthopedic insoles Other: Used 2x only. Has been washed. Name inside the sole has discolored or Faded Very good condition Unisex Fits best on Size 8 foot Originally $68 with tax