JZP-13.5-SC Rubber Shock Absorber: 13.5 kg Friction Damping Mount for Continuous Cyclic Loading Direct answer: The JZP-13.5-SC is a 60 mm diameter rubber-to-metal vibration isolator rated at 13.5 kg per mounting point, with a resonant frequency of 41.5±5 Hz, a damping ratio of 0.13 or above and static deflection held to 0.3 mm or less. It is specified for equipment that repeats load cycles for years rather than months. What does friction damping contribute in this design?