An ultra-short-throw (UST) projector is a type of projector that can project a large image maximum up to 8 feet screen size or wall from a very short distance. UST projectors can be placed close to the screen or wall, often just a few inches away. They are commonly used in classrooms, boardrooms, training room and other environments where space is limited. One of the advantages of UST projectors is that they eliminate issues like shadows on the screen caused by people walking in front of the projector. They often use specialized lenses and mirrors to achieve the ultra-short throw capabilities.