Hello scyto,
We have harnesses that can aggregate up to three CTs into one Spyder input. We offer additional CT sets (snap on style) in our online store, or you could buy another Spyder set. We do not offer the Spyder CTs separately from the set. The TED Pro Commercial system uses larger MTUs that have ethernet capability. The maximum number of MTUs and Spyders is the same, however, we also have harnesses for these MTUs as well, that can be used to aggregate CT inputs. The downside of aggregation is the loss of granularity, as there is no way to separate the data by CTs when they are on a harness.
I hope this better answers your questions, and I apologize for not understanding your question earlier.
TED Forum Support