Nylon is a non-magnetic material, with an all nylon pulley (no metal hub) there is no magnetic signature. This makes nylon ideal for use in applications where strong magnetic fields are present, like Magnetic Resonance Imagining (MRI) machines. Additionally, nylon is FDA approved for both foodservice and medical applications. Learn more about the benefits of nylon pulleys by downloading our white paper by clicking here: https://www.torquetrans.com/nylon-vs-metal-pulleys