NOK 5G21 Gateway Battery Backup

dilbert: the link was in the post prior to the picture you replied to. However, *that unit* shows as unavailable on Amazon, which is why I provided some additional options. However, if anyone finds any additional devices (12VDC UPS), that would be great, especially if they are cheaper. Also we need to know if the router requires a 5.5x2.5mm or 5.5x2.1mm or another size (I have no way to measure the ID). Seems 2.1mm inside is more common than 2.5mm but adapters may not be difficult to find.