Zappos and Walmart have a wide selection of knit hats available for purchase, including many different patterns and colors of two-gauge-stitch knit hats to choose from. Both outlets have options for men, women and children.
As of 2015, Zappos' selection offers hats in a wide variety of price points, starting under $20 and ranging up to several hundred dollars. Walmart's offerings are more economical, with most hats coming in at less than $30.
In knitting, gauge refers to the number of stitches per inch and can vary greatly, depending on the thickness of the yarn used, the width of the needles used, and the pattern of stitches used.