The (often called the "Keystick" or "Key Identifier") is a specialized sewing machine accessory designed to solve a specific problem: remembering which presser foot goes with which stitch setting.
If you need the key ID for a Brother PS-300B (sewing/serger/embroidery controller or similar accessory), here's how to locate it and what to include in your post when asking for help or replacement keys. brother ps300b key id
the software for the first time, or are you having trouble finding your specific Key ID Upgrade Procedure - Industrial Sewing Machine | Brother Brother PS300B "Key ID" The (often called the