This Projection Alarm Clock sets to the U.S. atomic clock to maintain absolute time accuracy. It also monitors indoor temperature and humidity, and outdoor temperature with a wireless sensor. The projection arm projects time and/or outdoor temperature onto the wall or ceiling (projection can be rotated). The time alarm with snooze keeps you always on time. Tip if you have trouble getting the sensor to work: 1.Bring both units inside and have the units 3-5 feet apart with nothing in-between them. 2.Remove the batteries from both units. 3.Press one of the buttons on the display at least 20 times to clear all memory. Verify that the display is blank before proceeding. 4.Using a good quality alkaline battery place them back into the remote sensor; making sure they are installed according to the diagrams in the battery compartment. Next, taking care not to press any buttons, reinstall the batteries in the display according to the diagram in the battery compartment. 5.Do not press any buttons for at least 15 minutes after installing the batteries. (Let them establish a good connection.) 6.An outdoor temperature should be showing on your display. You can now put your outdoor sensor back outside