size

This chart is for use with Men's Polaris, Sahara, Sahara II, Ridge, Beam, Shadow, Grit, Ibex, Flash, and Basecamp Base Layer Shirts.

How to measure:

Chest: Measure the fullest part of your chest, under your arms.
Waist: Measure around the fullest part of your waist.
Sleeve: Measure along the top of the arm from the top of your shoulder to your wrist.