Even with 16 available measurement ports on the RTS there may be configurations where the measurement ports simply are not enough. The Combiner/Splitter units are the solution to this problem and are available in two versions. CSU1 contains 4 pcs of 4-to-1 combiner/splitters and CSU2 contains 4 pcs of 2-to-1 combiner/splitters. Both units are 19" rack mountable and 3 HU high.