Cutex Brand 10 Aluminum Bobbins Pfaff 138, 238, 437, 438 Zig-zag Machines #91-168144-05 Set of 10 ALUMINUM BOBBINS for PFAFF Sewing Machines. Pfaff part # : 91-168144-05 bobbin is 22MM wide and 8.9MM thick Aluminum bobbins are considered the Top-End "Luxury Bobbins". They offer less resistance which translates to less drag to the bobbin thread tension These bobbins will fit PFAFF Industrial Sewing Machine models : 138, 234, 238, 331, 333, 335, 437, 438, 439, 460, 463, 480, 9063