Powerful vibration and an extra loud audible alarm work together to ensure you never sleep through your alarm again! Perfect for Deaf, hard of hearing, or heavy sleepers, this travel clock has very powerful vibration and an extra loud audible alarm to ensure you never sleep through your alarm again! The included clip attaches to your shirt or pillow so it stays put even when you?re tossing turning. Features: Powerful vibration 115 dB volume 12/24 hour option Easy-to-set function keys Manual backlight Requires (3) AA batteries (not included) One-year warranty Includes: Travel Clock Attachment clip Feature Details Primary Use Home Brand SquareGlow Mfg part # SGW-TCLK Warranty One Year Manufacturer Warranty Weight (lbs) 0.5 Battery operated? Yes (batteries required) Batteries included? No Battery details (3) AA batteries (not included) What's included? (1) Travel Clock, (1) Clip-on Alert Type(s) Vibration Flashing Light Loud Audible Yes No Yes Tone Control No Dual Alarms Yes Battery backup No Built-in USB charger No Bluetooth No Smartphone Compatibility iOS Android No No Expandable Yes