The Edge accessory system (EAS) was created with future expandability in mind. The architecture of the EAS allows users to connect multiple accessories daisy-chain style to the evolution CS or CTS. This means Edge can create optional accessories that can be added to the products by the owner at any time. An optional exhaust gas temperature (EGT) probe is one example of an optional accessory that will be offered by Edge. Look for a variety of other optional accessories to become available in the near future.,Edge Accessory System Starter Kit; w/15 in. EGT Cable For CS/CTS/CS2/CTS2; Expandable;