What these parts let you do, is to send a ir code (x10 ir code) that the x10 ir commander sees then sends a x10 powerline code to the x10 drycontact (power supply in line) and the drycontact is hooked to the msc-400 input (Voltage senser input) you could use a standard appliance module with a power supply plugged into it, that would trigger a smart macro in the msc-400.

Thanks
J.Todd