The FishEasy 350C can use two temperature sensors at the same time. It
also can use a speed sensor, but not at the same time as you are using a
secondary temp sensor. To use a speed sensor and a secondary tempera-
ture sensor at the same time, you will need a combination device.
If a second temp sensor is used, it must be the model TS-2U.
Primary temp sensor
built into transducer
Full Chart page showing dual temperature display.
external temp sensor
shown as T2