Size:71*68*13mm / 2.8*2.7*0.5 in Net weight:42g / 1.5oz(1pc) Material:high quality PC Frequency:433.92MHz Screen display number:001-999 Power supply :Built-in 3.7V lithium battery Charging period:3 hours Prompt modes:Flash, Bell, Vibration or any combination of them Package Includes: 5x Coaster Pager.