Plasma displays are generally considered to offer better dark-room viewing and wider viewing angles than LCD. Plasma TVs are available in sizes from 37 inches to over 100 inches, measured diagonally. Plasma can be vulnerable to burn-in, a phenomenon in which faint, permanent “ghosts” appear on displays that have maintained a fixed image for long periods of time. Examples of such images include the bars seen when watching 4:3 video on a widescreen display or the constantly running ticker seen on some shows or channels. Most newer models have burn-in prevention features, but these may not always be 100% effective. However, some plasma TVs also have the ability to remove burn-in should it occur.