The MOD-420 allows for a 4-20 ma connection on all 5.0 and 6.0 products. This module will allow for a 4-20mA signal transfer of the UV output to a remote device such as a data logger or computer. Simply plug the supplied cable into the “IEP” on the UV sensor module (or daisy chain to any other module used in the system). Two screw terminals are supplied to connect the wire that leads to receiving end of the signal. No wire is supplied, 16-22 AWG wire is required.