1.  Rack and pinion design, stable functioning.

2.  Double cylinder structure, double output could be achieved.

3.  The manufacturing precision of working platform is high, and is easy for installation , and is of precise orientation.

4.  The center of working platform has a through hole, and pipe can be located and passed through this hole;

5.  Two sides of cylinder have orientation holes, to facilitate installation.

6.  Two modes of buffer could be chosen, adjustment bolt buffer and internal shock absorber, the maximum buffer energy of internal shock absorber is 3-5 times that of adjustment bolt buffer.