The "Master Cylinder" driver is one of the most significant product enhancements from Shaver Manufacturing. The master cylinder provides a reservoir for the hydraulic oil that operates the driver, eliminating the need for routing a return hose through the hydraulic system.
All hydraulics are powered through the auxiliary ports, allowing for quick hook up and removal of the post driver. The driving ram channel has been deepened to allow for the placement of the master cylinder. When you purchase a master cylinder driver, you no longer have the hassle of plumbing the driver return hose, or the expense of a self contained hydraulic pump and motor system.
Note: this driver can also be mounted to a tractor, which eliminates the need for a return adapter to the tractor hydraulic system. One pair of tractor remote couplers would be required.