Steel spring reduces vibration transmissions most efficiently as performance improves with larger deflections. Spring deflections are 2 – 6 times better than the rubber products. Hangers have lds rubber cups under the springs and a projecting rubber bushing prevent sound transmission, even if hanger rods are not perfectly centered. Max load 76-125 lbs. 2-3/4″l x 3-3/4″w x 5-3/4″h overall dimensions.