Pillow Block Linear Ball Bearing IPPSN12G 3/4" Open - Self Aligning Precision PlusOpen Pillow Block Linear Ball Bearing with a 3 4" ID (inner diameter) featuring a crowned shell linear bearing for self alignment in an aluminum alloy housing. The IPPS products all come with a grease zerk fitting, a small hole in the pillow block which is also called a lubrication port. Temperature Range: 4 +176F ( 20 +80C) Variant ID Sizes: Available from 1 4" to 2 Inch Series, 8mm to 50mm Metric Interchangeable: Size interchangeable with industry