The internal mechanism of the twin tube design use hydraulic fluid and air so the damping piston actuator stroke is longer than mono shocks. This type of shocks is more complex so the cost of manufacturing it is higher but it provides better riding comfort and durability than the mono shocks. 
In addition, the twin shocks damping piston also constructed a super slow-speed valve that can absorb fine vibrations and during high speed cornering it¡¦s able to support the body.