Grease lubricates the bearing so it is recommended for lineshaft applications as well as gravity applications. The body of the bearing is made from 300 series stainless steel to prevent rust and corrosion. The balls are made from 400 series stainless steel for tighter tolerances and higher load capacity. The grease creates rotational drag so it is not recommended for extremely light weight gravity applications. The lack of seals or shields reduces drag but offers no protection against dirt and debris. Not recommended for dirty or dusty environments. Not recommended for high speeds or CDLR.