Mountain equipment womens switch vest a hybrid vest with an insulated front and low profile grid fleece back for fast moving mountain sports highly breathable and fast drying polartec alpha insulation is combined with our lightweight 20d rs shell fabric in the front of the body for wind resistance pontetorto tecnopile 187 panels in the back and sides minimise bulk and dry even faster after a strenuous ascent specification lightweight 20d rs nylon outer fabric with mechanical stretch