Nikon Z7 is a nikon fullframe Mirrorless camera that features a modified version of Nikon D850 $2,996.95 sensor, the sensor is optimized to perform better in low-light condition compared to existing Nikon D850 DSLR. Take a look at the Rumored specification of the Nikon Z7 Mirrorless camera
Nikon Z7 Rumored Specification
BSI sensors, Hybrid 45 MP
5-axis in-body stabilization
9 FPS AF tracking
Memory cards: XQD and CF Express (ProGrade is coming with a CF Express card).
EVF: OLED 3.6MP
Limited AF performance compared to Nikon Z7
Advance AF tracking
430-450. The AF is supposed to be very fast.
The rear LCD screen is tiltable just like the Nikon D850.