The RSIC-SI-WHI can be used to isolate pencil rod or hanger wire. Currently available in 5, 10, 20, 40, 60, 80, and 120 lbs. options with 1″ deflection. The 40 lbs. spring can support two layers of 5/8″ Fire Code C with the springs spaced at 4’x2′ (2.5 lbs. x 2 layers x 8 sq. ft. = 40 lbs.). The 80 lbs. spring can support two layers of 5/8″ Fire Code C with the springs spaced at 4’x4′ (2.5 lbs. x 2 layers x 16 sq. ft. = 80 lbs.).