This module adds vibrate alerts to a Blackout Comms communicator. If you are following the T-Deck DIY Build Guide, this is the module you want for vibrate alerts.
 
The Blackout Comms firmware automatically recognizes this module and uses it.
 
If you're doing your own development with it, check the Sparkfun Guide for more information about this module.
 
Note that your enclosure must have room for it and you must be using I2C instead of UART.