This small size vibration motor is suitable for a silent indicator in your project, just like your phone’s silent mode. It is very easy to operate, just give the module a 5V HIGH-level  input on the “IN” pin, it will just work. You can also use PWM signal to get different levels of vibration effects.
 
Specifications:
Operating Voltage: 3.0 - 5.3VDC
Operating Current: Max. 60mA
Start-up Current: max. 90mA
Insulation Resistance: 10Mohm
Dimension: 24 x 32 x 4.8mm
Weight: 2.7g