New Balance Sock Sizes
Sock Size	US Men's Shoe Size	US Women's Shoe Size
M	7.5-9	6-9.5
L	9.5-12.5	10-12

Sock Geek Says:

Lightweight sock that works best in hot weather climates or with low volume shoes.  Lightning Dry® technology for moisture management.  Seamless toe for seamfree comfort.  Mesh knit ventilation allows your feet to breathe.  Compression arch support -- stability and comfort by keeping fabric tight.  "Y" heel pocket for perfect fit.  Medium density 1/2 cushion footbed provides under foot comfort and impact resistance.

NB Cool Trainer Sock Specs

Sock Fibers:

80% - Polyester
15% - Acrylic
3% - Nylon
2% - Spandex