Call yourself a mountaineer? If so, the Arc’teryx Epsilon SV Jacket is an essential item in your kit. This highly breathable, lightly insulated jacket is built for the high aerobic mountaineer through and through. Constructed with a Bonded Polyester Fleece textile, the Epsilon SV provides moderate warmth while efficiently breathing while you’re on the move. The polyester construction sheds precipitation, wicks moisture and dries quickly for long lasting comfort.