Ultra short throw technology is a feature of many flagship 4K projectors. This greatly reduces the distance between projector and surface (walls, ceilings, etc.).This laser projector tends to produce sharp images. However, it can be more expensive than a regular or long-throw model.Ultra-short throw, or 'UST', is a space-saving technique that keeps your projector exactly where you would place a TV. It also means you won't have to mount a projector to your ceiling. People moving about a room will be less likely to block the images.The decision is up to you.