Smartwool W CLASSIC THERMAL MERINO BL BOTTOM BOXED Change can be a good thing. Smartwool has improved the cut of the W CLASSIC THERMAL MERINO BL BOTTOM BOXED 100% Merino wool underpants - they have new side seams and a curved seam in the back, which narrows and prevents the fabric from stretching. The underpants are designed so that you can do what you love and still feel comfortable. They regulate body temperature and Merino wool is incredibly soft. Smartwool W CLASSIC THERMAL MERINO BL BOTTOM BOXED