Loads of protection the old school way: silicone, and more silicone.
OtterBox is known for quite intricate multi-layer cases providing maximum protection. The Prefix series actually shares some high-tech solutions inside, but on the outside it looks like your average rather bulky silicone case. There is a ribcage structure in the back of the case, and around the sides. This is made from hard TPU, and gives the case more rigidity. This ribcage also creates an unwanted wear pattern directly on the back of the phone. With extended usage this might be hard to just polish away. It takes just a couple of hours for the case to start marking the phone.
For protection the Prefix gets the job done for both scratch, and impact damages. The entire phone is covered by thick rubberized silicone. If dropped the phone simply bounces a bit. The added grip means you won’t be as prone to dropping it though. To complete the protection a screen film protector is also included. This is however hard to use with the case, as the edges of the case tends to dig under the screen protector creating bubbles.
There are well-sized cut-outs for the mute switch, and camera. The volume controls, and silent button are covered in silicone that is a bit thick and unresponsive. The silicone around the bottom is a bit thin, and can feel flimsy.
The Prefix is definitely not the best work I have seen form OtterBox. Thick chunky silicone is never a good look no matter how good it feels in the hand. The major issue I have with the Prefix is the marks left by the ribcage design.