The AW & AWH styles are recommended to be used directly under most HVAC equipment and in conjunction with structural steel bases and concrete inertia blocks. Design FLS vertically restrained spring isolation mounts are recommended as being a noise and vibration isolator for mechanical equipment Found near critically peaceful areas, https://edgarfzunf.blazingblog.com/39165716/detailed-notes-on-spring-isolator-for-mechanical-equipment