- As a type of FSL series, it uses SMA2 type (static deflection of 50mm) and prevents damage and distortion of the equipment and pipe. The upper housing (compression plate) has a restrain bolt and level bolt, while the CR-type acoustical non skid pad on the bottom is to prevent the transfer of high-frequency vibration).
- Though it has same features as FSL2 type, it uses a spring with the static deflection of
75mm and therefore, it is used when more delicate vibration control is required. For
example, it is mounted on equipment installed on a rooftop having the average slab length
of 6-9 m and natural frequency less than 8.3 Hz (500RPM). In such a case, the natural
frequency of the vibration control system needs to have the natural frequency of less than
2 Hz and at least 60 mm static deflection. FSA3 series spring is used in this model.