A plug-in relay output module for the reactor control system, carried by Trojan under part number 03805. It accepts a low-level digital output from the controller — 24 V or 5 V logic — and switches an isolated contact, so the control electronics can operate external equipment such as a valve, contactor, alarm or dosing pump without the switched load reaching the controller’s outputs. Modules of this type are consumable rather than permanent: the relay contacts wear with every operation, and a channel that has stopped switching while the controller is otherwise healthy is normally cured by changing the module, not the controller board behind it. Item number 15176-0118. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.