Asus Zenfone 2 (5.5", Ze550ml/ze551ml) Case,CAPY Ultra Thin Slim Fit Aluminum Alloy Metal Bumper Case Luxury Looking, Lightweight, Durable, and Snug Fit (Black) Easy installation with unlock buckle design. Ultra thin aluminum alloy design with high quality oxidation. Lightweight weight at only .4 ounces. Full aluminum power and volume button built into the bumper.