Another excellent option for the OnePlus 5T is the official Silicone case from OnePlus themselves. This isn't just your typical cheap silicone case either. They've added a few important changes.
For one, the OnePlus 5T Silicone case comes with three layers of Silicone for added protection and shock absorption. Then, there's a soft microfiber lining on the inside of the phone. This keeps the entire device clean, scratch-free, and further protects from forces when dropped.
The camera, screen, and buttons all have raised edges to keep everything safe. This case comes in Black or a Shiny OnePlus Red.
Buy it from OnePlus for $19.95