Features of the Smartwool Women's PhD Light 1/4 Zip Top Minimal merrow seam construction provides superior durability and is soft against skin Integrated thumbhole openings for additional coverage 7in. Center front zipper with semi-locking logo slider and chin guard Built for Performance in the Highest degree Lightweight merino blend provides stretch and recovery, breathability and quick drying Body-mapped mesh panels for additional breathability and moisture management Adds visibility in low light conditions