Castaway comes in several different colors and two sizes: the 5.8-inch version and the 6.3-inch version.
The mobile phone protection shell is divided into two parts, one is the standard shell, the user puts the mobile phone in, the other part holds the second screen.
The screen will be physically connected to the user's smartphone via a 360 degree magnetic hinge, and they will communicate via Bluetooth and Wi Fi. Castaway poster the case comes with batteries, SD card slots and even headphone jacks.
There's also a built-in Chrome OS system, and the castaway team says the device can last up to 10 hours on a single charge.
The device is only available in two sizes, but the cast away team says the case should be available for 95% of devices, but there is no evidence to support that, just saying devices work doesn't mean they will succeed. The final retail price of the 5.8-inch version is $249 (about $1747), while the final retail price of the 6.3-inch version is $269 (about $1888), if the crowdfunding is successful.
Supporters will be able to buy the case for $189 (1326 yuan) and $199 (1396 yuan), respectively.
If all goes according to plan, the protective shell should be delivered in spring 2020.