The Sony xperia m5 has a plastic back instead of aluminium or metal. The reduced build quality means a better price point but at a loss of toughness. My M5 was less than 30 days old when a split appeared on the rear of the phone. This is unacceptable particularly since it was sold as a waterproof phone. Both Sony and my telco provider were unhelpful saying such damage is not covered under warranty. I would ask what does their warranty actually cover if these sorts of problems are left to the consumer to work out? It's a design fault of the phone and they don't want to deal with it. This is the last time I will buy a Sony make phone. I had to buy a temporary replacement budget phone and it only cost me $30. It is a full LCD 4inch smartphone and it works fine. What a joke these so called flagships have let themselves become. My xperia was.. $600