Hi, this video shows you the PS4 U.
My DIY attempt at the PS4 Wii U style Gamepad. This allows you to play your PS4 locally within Bluetooth range on a handheld screen with no lag (very little, not noticable). If using near your console then this option is better than Remote Play as you have a full 1080p even on PS4 and PS4 slim and no latency.
It has a 1080p 10″ screen which looks lovely. By using Wireless HDMI and the Nintendo Switch Joy-Con it makes it possible to mimic the best feature of the Wii U which is the 2nd handheld screen.
Many thanks Vince
The PS4 U Gamepad. DIY Handheld PS4 gaming with NO LAG!