The Raspberry Pi 400 may be the most powerful machine that the Pi Foundation has ever released, but the Foundation does not include a display with which to use it. However, Waveshare is on hand with two kits for the Pi 400 that do exactly that. Currently, the company offers 7-inch and 13.3-inch displays, which both screens support capacitive touch input. However, the 7-inch version only supports up to 5 simultaneous inputs, whereas the 13.3-inch one supports up to 10.
The 13.3-inch display also features a built-in speaker, which the 7-inch version lacks. Both are connected to the Pi 400 via an HDMI input. The 7-inch model operates natively at 1,064 x 600 pixels, while the 13.3-inch panel offers a full 1080p.
Waveshare also includes all the necessary accessories to get the Pi 400 working, including an HDMI cable, a power cable and all the parts that the Pi Foundation bundles with the Pi 400. The Kit with a 7-inch display costs US$179.99, making it a fair bit cheaper than the US$266.99 price of the 13.3-inch version.
Source(s)
Waveshare (1) (2) via CNX Software & Liliputing