New Balance Sock Sizes
Sock Size	US Men's Shoe Size	US Women's Shoe Size
M	7.5-9	6-9.5
XL	13-15	12+

Sock Geek Says:

Left/Right engineering in toe box for anatomically correct fit.  Tactel^® Nylon gives added comfort through effective moisture management.  Strategic cushioning -- selectively cushioned to provide shock absorption in important strike zones.  Compression arch support adds stability and comfort by keeping fabrics in place.  Mesh venting for maximum breathability.

NB Second Skin Racer Sock Specs

Sock Fibers:

95% - Tactel^® Nylon
5% - Lycra^® Spandex