Federal Signal's Models 300CK and 300CKS are the connector kits that allow SelecTone speaker/amplifiers to be used with SelecTone Command Units.

When creating a SelecTone system based on a Command Center, rather than individual tone modules, each SelecTone speaker/amplifier requires a connector kit.

The Model 300CK connector kit is a circuit board which is installed in the tone module receptacle of a SelecTone speaker/amplifier, making it possible to transfer audio signals from the command unit to the individual speaker/amplifier.

Similarly, the Model 300CKS Supervised Connector Kit is required for each speaker/amplifier in a supervised SelecTone system. Model 300CKS receives the audio signal from the Model 300SSC command unit and conducts the signal to the speaker/amplifier.

Connector kits are required for every SelecTone speaker/amplifier unit in a SelecTone employee alarm and communication system. The Model 300CK is used in non–supervised SelecTone systems with Models 300MB, 300MC, 300VSC–1, 300VSC–1044SB and 300SCW–1. The Model 300CKS supervised connector kit is used with the Model 300SSC supervised command unit.