Atomic Projection Alarm Clock with IN/OUT Temperature and USB Charging. Projects time/temp on wall or ceiling, displays indoor temp ( F/ C) and outdoor temp ( F/ C) Atomic Time & Date sets itself, Time Alarm with Snooze, EL Backlight, USB Charging Port, Projection rotates in 90 degree increments, Projection options: (1) Default: toggle between time & temp., (2) time only, or (3) temp. only, Light up color display backlight and projection with a press of a button using battery power OR continuous light with AC adapter (ON /OFF option) Backlight and projection settings: High, low and off, 12/24 hour time with minutes, Snooze alarm and alarm icon, Calendar: day, date, IN / OUT temperature ( F / C) with trend arrow, Low battery icon for clock & sensor, 5.0V AC adapter (included) for primary power and battery backup, Battery life is over 24 months when using the AC adapter Dimensions:Receiver: 5.23" L x 1.96" W x 4.33" H Transmitter: 1.58" L x 0.83" W x 5.08" H