The RTC Multi-link is a hardware/software networking solution for the Commodore 8-bit link of computers, and compatible with the following machines:

Commodore 64 Breadbin (long board)
Commodore 64c Slim case (short board)
Commodore SX-64 (Executive/portable)
Commodore 128
Individual Computers Reloaded V1
Individual Computers Reloaded V2
Gideon's Ultimate 64 (all versions)

This product/item should be considered the complete hardware starter pack, that will allow you to network one computer to a master computer.  The master computer manages the network, and is required.  You will receive the hardware shown in the photo.

The "grey" cased cartridge is the "Master" control cartridge, that is inserted into the computer that will function as the master control machine.  This must be a Commodore 64, and cannot be a 128.  The remaining black cartridge is the satellite cartridge.  Each satellite cartridge you own plugs into the cartridge port of each respective machine to become part of the network.  The ribbon cable connects the grey master cartridge to the satellite cartridge.  The order in which they are connected is not important.  The first cable plugs into the grey master cartridge, and the other end of it connects to the first computer in the network.  If you purchase more satellite cartridges, then the next satellite is linked by daisy chaining.  

The cable that plugs into the top of the cartridge only plugs in one way, as the connector is keyed.  The other end of the cable is marked as to which side is up.

Follow the instruction manual available for download for complete network setup and configuration.  The cable spool and cable clip may be a different color than shown.  Master cartridge will be grey as shown, and satellite cartridge will be black as shown.

NOTE: Due to the weight of this product, an additional shipping surcharge must be added to cover the higher than normal cost of this due to the weight.  Please select the appropriate surcharge for your region.  If this rate ends up being an overcharge, you will be refunded the difference.