Heart Horse 2-Button Car Remote Control Flip Key Fob Case Replacement with 433MHz ID46 Chip and Uncut HU100 Blade for Opel/Vauxhall Astra, Insignia, Mokka, Adam, Corsa, Viva, and Zafira Key Case: Amazon.co.uk:
How To Change a Vauxhall / Opel Key Battery - YouTube
How to Change the Battery in a Vauxhall Key Fob - Opel Car Key Battery Replacement Tutorial - YouTube