The RSIC-SI-CRC X2Low Profile Spring Isolator is designed for use in a ceiling under Concrete, Steel or Wood Floor Ceiling systems. The RSIC-SI-CRC X2 Low Profile isolator is available in 5 lb, 10 lb, 20 lb, 40 lb, 80 lb, 120 lb, and 160 lb spring rates. The Spring is fully assembled and preloaded. The RSIC-SI-CRC X2 Low Profile is adjustable starting with a 3" drop. To increase the cavity depth, add all thread and a coupling nut to extend the RSIC-SI-CRC X2 Low Profile further away from the floor system. SPECIFICATIONS: Acoustical Design Load: 5 Lb to 160LbTotal Deflection:: 1 InchDouble Deflection: Yes (12")Adjustable: YesCavity Min: 3"Cavity Max: VariableAdjustment Limit: Extension LengthUse On Ceilings: YesUse On Walls: NoNew Construction: YesRetro Fit: YesShips Pre-assembled: YesBENEFITS: RSIC-SI-CRC reduces vibrations as low as 5 hz.Rubber bushings dampen the spring for highest acoustical performance.Reduced labor expense with fully assembled and pre-calibrated isolators.RSIC-SI-CRC is engineered for full 1" spring deflection.