Pluggable Connectors Specifications for RelayPros Interface

I have a few RelayPros Interfaces and to better maintain the wiring of the Relay Channels I would like to know the specifications for pluggable connectors that I can fit in the connectors that come with the Relay Interface.

This is the RelayPros interface I am using:

I want to buy the pluggable connectors on Digikey, so I need to know what is the Pitch between each connector to order the proper parts.

I am attaching a picture of the connectors I need.