The Bobbin B1811-771-000 A for Buttonhole (Part #B1811-771-000 A) is a genuine JACK original replacement part designed for JACK JKT-781, JKT-782, JKT-783 and JKT-1790 series button sewing machines, as well as Juki LBH-771, LBH-780 and Speedway SW781D, SW5780AS series models. Manufactured to OEM specifications for precise fit and reliable performance. Equivalent Part Numbers JACK: B1811-771-000 A Compatible: B1811-771-000 B Compatible Machines This part fits the following industrial sewing machine models: JUKI: LBH-771, LBH-780, LBH-1790 SPEEDWAY: SW781D, SW5780AS JACK: JKT-781, JKT-782, JKT-783, JKT-1790 Technical Specifications Brand JACK Part Number B1811-771-000 A Part Type Bobbins Condition New – OEM Original Looking for a replacement bobbin b1811-771-000 a for your JACK JKT-781 or JKT-782 button sewing machine? This genuine OEM part is also compatible with Juki LBH-771 and Speedway SW781D series machines. Shop with confidence — all parts ship from Miami, FL. ⚠️ Compatibility Notice: Always verify your machine model and subclass number before ordering. Part numbers and compatibility are provided as a reference only. Supra Sewing is not responsible for purchases made without confirming compatibility with your specific machine. All sales on replacement parts are final.