Rock is a third party case and cover manufacturer that has created some of the best phone cases to ever hit the market. They commonly create their Defender and Commuter series cases to protect phones. The Rock Galaxy S4 Commuter Case will have a hard shell composite body with a silicone soft shell surrounding the inner shell. It is a smaller, thinner case that offers quality protection. It is usually less expensive and less bulky than the Defender series. The Rock Galaxy S4 Defender Case is their thicker case that uses a little more protection. It comes with a built in screen protector, and another layer of protection of soft core foam inside the hard shell case. Rock now has a new series of cases called the Rock Reflex Case that has two pieces that slide together for lightweight, fast protection that is easy to put on and take off your phone. The Rock cases are incredibly dependable, and are a great investment to protect your phone. Rock is the case that I personally have used for the past five years, and even when the silicone outer shell started to show wear, Rock sent a replacement free of charge. They are great phone cases.
At last, if you would like rock covers, you can input keywords: "ROCK Big City Series Leather Flip Case Cover for Samsung Galaxy S4" on Amazon.