This is the ZZ-2 ZW-GM ZWagz Strobe Light Interface.

A Light Controller-connected module for select NEW GM vehicles that allows you to flash the OEM lights with a simple press of button.  

The ZW-GM is a plug and play unit at the OE Light Control Module (beside the BCM) which allows you to flash the factory lights in 3 different flash patterns. All patterns are selectable using the high-beam lever. The unit can also be triggered via the provided push button, wire trigger (up-fitter trucks) or using the OEM keyfob!

Features:

• 3 unique flash patterns, including a strobe-mode on each
  
• Plug & Play
• Optional: Push button activation, up-fitter wire activation, keyfob activation
  
• Easy activation using OEM controls
• Outputs mimic flash patterns for external lighting systems

Vehicle Compatibility: 

• Chevy Silverado 2014-2023 (pre-facelift)
• GMC Sierra 2014-2023 (pre-facelift)
• Chevy Tahoe 2018-2020
• GMC Suburban 2018-2020