Upper Looper For Brother Portable Sergers. Part # : X77781001 (X77781-001) High quality replacement parts. Fits Brother serger models : 925D, 929D, 1034D, 1034DAV, 1134D, 1134DW, 2034D, 3034D, 4234D, 4234DT, 5234RPW, DZ1234, M1034D, M1034DAV