If the extracted files are guitar patches, this guide shows you how to import them into your device using Boss Tone Studio: Boss GT-1 Tutorial - How to Import & Export Patches GuitarNTabs YouTube• Jul 14, 2022

The file appears to be a specific segment of a multi-part RAR archive, likely containing firmware, software, or a sound library for the Go to product viewer dialog for this item. Guitar Effects Processor. How to Use This File

To make this piece "useful," you cannot open it individually. You must follow these steps to extract the full content:

: An update for the hardware unit itself.

: Based on the "GT1.63" naming convention, this is likely:

Once extracted, if the content consists of patches (usually .tsl files), you can manage them using official tools:

: Open part01.rar (or the first file in the sequence) using software like WinRAR or 7-Zip . The software will automatically bridge all "parts" together to recreate the original 2GB+ file.

If you are having trouble extracting the file, could you let me know: Do you have (part1, part2, etc.)?