This projection clock was rated The Best by the Hammacher Schlemmer Institute because it provided the most accurate time and temperature and was the easiest to use. Its remote outdoor and indoor thermometers were the most accurate, varying by only 0.7º F and 0.8º F, respectively, while lesser models were off by as much as 2.6º F. Also ranked as the easiest projection clock to use, it has simple buttons and an intuitive menu for adjusting the alarm, brightness, and time. It projects the time and temperature on a wall or ceiling up to 10' away. Also includes superior features such as an alarm with snooze, a nap timer, calendar, moon phase icons, and an adjustable backlight. AC adapter; remote sensor requires two AA batteries. Clock 4" H x 6 3/4" W x 1 1/2" D, sensor 3 3/4" H x 2" W x 1 1/4" D.