The compatible with SHARP Projection Alarm Clock with Sleep Sounds offers the option to display the time on your ceiling or wall with the 90° adjustable projection arm. Fall asleep to your choice of eight different soothing sleep sounds. Featured sounds include: Campfire, Thunder, Rain, Ocean, White Noise, Fan, Stream, Rainforest. The clock has dual alarms giving you the option to set two separate alarm times. For example, you could set one alarm for weekday wake times and the other for weekends This clock is electric operated; the battery backup does not power the clock. The battery backup is used for storing the time and alarm settings if the power is interrupted. During battery backup the clock' s display will not be lit. Once the power is restored the display will re-light. Check the time to make sure it is accurate and adjust if necessary. Product Dimensions: 6. 85 x 4. 2 x 4. 5 Projection Clock onto Ceiling Soothing Sleep Sounds Easy to Read LCD Display Dimmer Control Dual Alarms