For moderate to heavy loads, speed, and vibration. All bearings are equipped with close tolerance stainless steel metal shields, an internal silicone contact seal (B-type), and factory lubricated with a NSF H1 certified ISO VG 220 PAO base oil, NLGI No. 2, Aluminum Complex thickened grease. Suitable for general use in food processing with moderate washdown requirements and can be PM'd. 304 Stainless steel housings provide excellent chemical and corrosion resistance capable of resisting many acids, fats and most food and beverage processing chemicals. They are also very strong and useful for carrying the high stress found near drives, belt and chain tensioners.