Bishop-Wisecarver's longest-lasting product yet, often capable of 2.5x or more cycles than comparable grease-filled wheels. Instead of using grease to retain the oil for lubricating the internal bearings, this wheel uses an oil-impregnated solid polymer matrix. Whereas dust, debris, and wear particles can get trapped by grease and degrade the effectiveness of the oil, the solid polymer matrix keeps particles out. It also resists moisture and chemicals better, retains oil much better (even under washdown conditions), and holds up to 30% more oil compared to grease. Made from AISI 440C stainless steel with the latest seal shield technology for exceptional protection of the wheel's inner components. Polymer matrix provides enhanced resistance to debris and wear particles, moisture, humidity, and chemicals (including acids, lyes, and solvents). Oil is H1 food grade, suitable for incidental food contact and use in food processing, food packaging, pharmaceutical applications, and more.