. The "v0291 13" likely refers to a specific version or an error code (such as Error 1013) associated with these utilities.
Sony Mobile uses the format for their firmware updates. While official channels like "Xperia Companion" only allow updating to the latest approved version, Flashtool allows users to: flashtool v0291 13
: It is recommended to download official builds only from the Androxyde GitHub repository to ensure the software hasn't been tampered with. flashtool v0291 13