Designed for single-hand use, this 4X monocular telescope magnifier is ideal for museums, sporting events, reading street signs, and many other leisure activities. Simply squeeze the casing once and the Microlux expands for use. Squeeze it once again, and it retracts into its protective case. An additional feature includes the ability to use it in reverse so that it acts as a field expander - ideal for those with restricted visual fields. A case is included. Focal range is 10ft to infinity; visual field is 13 degrees.