The SINGER Class 66 Metal Bobbins includes 12 metal bobbins to serve as replacements for the following compatible machines: brands compatible with SINGER models 66-1 through 66-18, 99CL, 185, 192, 201, 609, 717, and other top drop-in bobbin sewing machines. Consult your machine’s manual to ensure correct bobbin size. Use the bobbins beneath the needle plate in automatic sewing machines to wind the thread for your embroidery projects. Details: Silver 5.25" x 6" x 1.72" 12 count Metal