Twin Closed Plain Linear Bearing Pillow Blocks feature self-lubricating Simplicity® Plain Linear Bearings housed in a self-aligning design. The double size is the equivalent of two single-sized pillow blocks back to back for enhanced support and stability. The standard FrelonGOLD® bearing liner is engineered to withstand harsh, high-temperature environments, while optional liners, such as Frelon®J for corrosive chemicals and Frelon®W for FDA compliance, are also available.