The RSIC-SI-WHI can be used to isolate pencil rod or hanger wire. Currently available in 5, 10, 20, 40, 60, 80, 120, and 160 lb options with 1″ deflection. The 40# spring can support two layers of 5/8″ Fire Code C with the Springs spaced at 4’x2′ (2.5# x 2 layers x 8 Sq.Ft. = 40 pounds). The 80# spring can support two layers of 5/8″ Fire Code C with the Springs spaced at 4’x4′ (2.5# x 2 layers x 16 Sq.Ft. = 80 pounds). The 160 pound spring can support double the load or double the distance with a heavy duty Carrier Channel such as 3-5/8″ x 20 gauge or heavier steel stud the spring can be at 4′ x 8′ OC.