Pillow Block Linear Ball Bearing IPPS32G 2" Closed, Self-Aligning, Lubrication PortLinear ball bearing pillow block, closed, with a 2" inner diameter (ID) self aligning bearing inside an aluminum alloy housing with a lubrication port called a "grease zerk fitting" on the side. Interchangeable with industry standards, this bearing has a low coefficient of friction, a heat treated alloy steel shell for durability, and a resin retainer polymer cage to reduce noise. Grease zerk fitting lubrication port on the side Temperature Range: 4