There are a number of manufacturers of 4K Ultra HD TVs. 4K means that the TV display is a resolution of 3840 x 2160--that's the equivalent of 8294400 pixels. That means that for every pixel of a 1080p display, a 4K display has 4 pixels. But a big factor in buying a 4K TV is the size of the display. Panasonic makes a 50" 4K HD TV. Some of the major brands are Panasonic, Samsung, LG, Sony, and Hitachi. You can find 4K TVs with SCART sockets, as well as VGA and HDMI outputs. They will also allow you to hook up a Blu-ray player or sound bars. They will also usually be Smart TVs, with Internet connectivity and interactive features, with an operating system much like a computer. A Samsung TV will use an index called PQI, or Picture Quality Index. The higher rated TVs will produce a higher rate of frames per second and offer a better contrast between dark and light colors.