Double Roller Pillow Block Bearing DPB-24-OPN 1.5" IDDouble Roller Bearing Pillow Block (DPB) for a 1. 5" diameter linear shaft features two sets of 3 opposing roller bearings while maintaining the open bearing style standard size profile of a Single Roller Pillow Block (SPB). In contrast, a Twin Roller Pillow Block (TWN) also has two sets of 3 opposing roller bearings, but the TWN blocks are larger, resembling two SPBs fused together. Double the load capacity of a Single Roller Bearing (SPB) Pillow