Alpine Outfitters Urban Trail Adjustable Harness. Simply the most comfortable, safe, and durable harness made. Designed for all active dogs and a wide variety of dog-powered activities, including mushing, hiking, running, biking, roller blading, skijoring, canicross, tracking, and more…or just a relaxing walk around the neighborhood with your canine companion. For a proper fit, it is IMPERATIVE that you measure your dog per the Measuring Instructions provided, then select proper size from the Size Chart.