A reciprocating linear encoder includes a linear encoder and a sensor. The system includes a hydraulic circuit including a master cylinder, a control valve, an accumulator, a first one-way valve and a slave cylinder. The head can be coupled to the handle. The decoration ball can be easily stored away when the polygonal grates and the panels are knocked down occupying only a small space, thus the storage and transportation costs can be reduced considerably. To that end, a compensation spring is provided on the compensation joint.