audioOS 9.9.12.2 (build 16E227) is an official Apple over-the-air update for the HomePod, released on 2019-03-25T19:21:09Z. The update package is 399.85 MB. This is a delta (partial) update that requires 12.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0c5d1a7bf69d7f52c70d2c59b0fe6ca44401e79e.zip.