Magnetic Sewing Thread Lubricator Box For Sewing Machines. Reduce thread shredding with this handy oiling device. Simply sit or screw the magnetic oiler onto the top of the machine and run the thread through its reservoir to reduce thread shredding. Also helps to make thread tension more consistent. Use silicon lubricant for best results. Attaches to Sewing Machines using either the very powrful magnet or by fastening hold screw on the for thread spool pins. Up to 3 threads may be lubricated at one time. Each thread will be uniformly soaked with the contents of the box ( silicone oil- not included) Use to slove high heat, very thick material , inferior thread, and other demanding applications. Can use thread size up to #69 (T-70)