POLYGYR Joker POLYGYR universal HVAC controller with 5 analog inputs, 3 analog outputs, 2 digital outputs. Direct replacement by Synco RLU232 which has the same functionality with additional features, but is different in size and appearance. If all three control loops are required, an additional Synco RLU2.. is required. 
Info: the Synco RLU2.. units have a different setting configuration.