... Drum Vibratory Roller Hydraulic vibration system, double-frequency and double amplitude. Static linear load 425 N/cm JZZ20 Compactor, road roller9. ... strong power,low emission and low noise.2,The hydraulic vibration system,double-frequency and double amplitude,imported variable ... pump and imported motor.3,Rear wheel drive,hydraulic shift transmission with intelligent electric control,drive axles and ...