Nils Gretchen Sweater - Women's: Mix and match your layers with the zip front mock turtleneck Gretchen sweater. With diagonal rib detail, Gretchen is a timeless sweater to add to your ski wear collection. Pair with a white tee, leggings and boots for a classic look. Zip Front Mock Turtleneck Cardigan with Diagonal Rib Detail. 85% Rayon 15% Nylon.