audioOS 12.0 (build 16A366) is an official Apple over-the-air update for the HomePod (Unknown Model), released on 2018-09-17T17:11:55Z. The update package is 1.4 GB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0b4b3d3d1a6b880175547ead21ef98f707a60151.zip.