This new Karbon Bumper Case is a quality case from OnePlus crafted from DuPont™ Kevlar® fiber and premium rubber.
Pls refer to https://oneplus.net/hk/oneplus-5-karbon-bumper-case.
The package is still sealed. Its MSRP is $258. It's offered at $230, and can be traded in any of the MTR stations between Kwun Tong and Mongkok.
Pls PM me if interested.