This Mason HS-X-54 spring hanger vibration isolator suspends equipment, piping, or duct work from a ceiling to isolate vibration and noise. The hanger box is arc-welded steel for strength and durability. The acoustical spring cup is made of bridge-bearing natural rubber with a low dynamic stiffness to minimize noise and vibration, with a bushing projecting through the box to prevent steel-to-steel contact at the bolting site. The cup secures a heavy-duty steel spring for absorbing shock and supporting loads. The entrance for the lower rod to attach to the spring's top steel cup is the width of the inner diameter of the spring to protect the rubber acoustical cup from contact. This spring hanger vibration isolator should be installed with a rod gap on the underside for efficient operation and to compensate for minor misalignment. Upper and lower rods not included. This vibration isolator is suitable for use with pipe, duct work, or hanging ceilings.