The Mountain Jacket. Topo Designs' answer to the everyday jacket, perfect for out on the town, durable enough to wear on the trail. Inside pocket for phone, keys, full back zipped pocket for stashing gear without it getting in the way. Reversible zipper on the back pocket allows you to turn the jacket into pillow for camping or long plane flights. Waterproof, breathable nylon fabric and rolled seams help keep the elements at bay.Â Interior of ripstop nylon creates a smooth comfortable feel and acts as aÂ vapor barrier.