Pillow Block Linear Ball Bearing IPPSN08G 1/2" Open - Self Aligning Precision PlusOpen Pillow Block consisting of a Linear Ball Bearing with a 1 2" ID (inner diameter) crowned shell self aligning linear ball bearing inside a housing made of aluminum alloy. It is self aligning due to a crowned bearing shell inside the 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