Selling for twice the price of Belkin’s offering, Sports Armband’s construction and materials are typically Incase, and quite nice. The setup is pretty standard: the armband is made from a neoprene-like material, with a front pocket that holds the phone with a touch-through clear plastic cover, and the back has a Velcro-equipped adjustable band. The bottom has a single hole for the headphone port. Otherwise, your iPhone is completely sealed…