In the future, the devices will apparently allow us to do things like record and recall memories, and restore sight with implanted cameras where eyes used to be. "It's like a Fitbit in your skull with tiny wires," Musk said of the device. (As Buzzfeed reporter Ryan Mac pointed out on Twitter, millions of Fitbit accounts were recently exposed by hackers.)
The device will charge conductively, like an Apple Watch, which researchers say users could do while sleeping. It will, apparently, help us understand consciousness better, and even let people download their consciousness and upload it into a new body. It'll be implanted into users' bodies through automated surgery and will be "quite expensive" at launch, whenever that is, Musk said. "This is increasingly sounding like a Black Mirror episode … the future's gonna be weird."
It's worth noting that sharp minds have been working on this problem for a very long time. DARPA launched a similar project in 2013. It's still very much in the testing phase.