Progressive Suspension Aluminum body vintage shocks. These units are very trick in design and performance. Very well made and designed for vintage motorcycles. The lower chain side mount is machined in an offset position to give added clearance next to the chain to prevent contact. Just like the old S&W shocks, they are an oil emulsion design and provide years of trouble free performance. These units have compression and rebound dampening adjustment. Each set comes with bushings and an adjustment wrench.