We're working out what we think - we'll add our view here!
Sherpa Adventure Gear says:
With a 100 wt. two-sided brushed anti-pill fleece, the Rolpa Zip Tee is a lighter-weight version of our award-winning Sonam. An essential for all of winter's wanders, the Rolpa is perfect for warmer fall days and as a baselayer under your winter shell, and always with Nepal inspired detailing.