Device firmware summary
FTVDB catalogs 15 public firmware records for Fire 7 - 9th Gen (2019). The device is identified
by model KFMUWI and by firmware package
com.amazon.mustang.android.os. These identifiers help distinguish hardware that may have
similar retail names but receives a different firmware line.
The catalog currently spans Jun 3, 2019 through Jun 11, 2025. The latest version in the ordered list is
Fire OS 7.3.3.1 (PS7331/4463), with build code 31575863172 and a recorded date of Jun 11, 2025.
Compare the version label, numeric build code, and recorded date in the table below. Recorded dates describe the public source metadata in this catalog and are not an installation recommendation or a guarantee that an update applies to every device.