These alarm clocks have one special quality in common and that is availability to project the time, eventually information about a temperature, on a wall of a habitable room. Thanks to this advantage you can find out actual time, or indoor temperature just with one look at the wall, and without looking for your alarm clock and its buttons in the dark. It is possible to point the projector at any wall in a distance of several meters. Most of the JVD alarm clocks have also a function of spin, which means that the projected numbers can turn to a legible position. The newest models have automatic sensor of switching off the projecting during the daylight which helps the projector to live longer.