"Hydraulic Elements and Systems" is a private joint-stock company. The company was established on 17th June 1968 with headquarters in Yambol a picturesque town in the South-East part of Bulgaria which has been developing as a center of precise power machine building since the middle of the century.

HES Plc. designs, produces and services hydraulic cylinders:
- PISTON CYLINDERS - single-acting and double-acting (with and/or without damping at the end of the stroke), with diameter of the piston rod from 30mm to 300mm and maximum length of the stroke up to 2500mm;