This listing is for 8 piece/s.A bushing is also known as a bush is an independent plain bearing inserted into a housing to provide a bearing surface for rotary applications. This is the common form of a plain bearing. The common designs would include split, solid and clenched bushings. They are only a "sleeve" of material with an inner diameter, length and outer diameter They also help to constrain and restrain the motion of the parts. Sometimes, they are also known as a plain bearing. Bushings are used to line holes in stationary parts of a mechanism. They are particularly effective in spreading friction and wearing over the surface of the bushing as opposed to directing into a single spot. The main advantage of a bushing, as compared to a solid connection, is less noise and vibration are transmitted. Another advantage is that they require little to no lubrication. Specifications P Value [Max]: 20000 Psi Temperature Range [Min]: -328 °F Groove Type: No Groove V Value [Max]: 1000 Sfpm Material: PTFE Length: 22 mm Temperature Range [Max]: 536 °F Inch/Metric: Metric Flange O.D: 30 mm I.D: 20 mm Max. Static Pressure: 36,000 Psi Lubrication: Self-Lubricating Has Flange: Yes Bore Type: Round Bore Pv Value [Max]: 50000 O.D: 23 mm Flange Thickness: 1 1/2 in Max. Dynamic Pressure: 20,000 Psi