CAT 206-2700 Engine Control Module
Product and application
CAT 206-2700 is listed as an engine control module. Public records point to a CAT 3126 application. That is an application lead, not a promise for every 3126 installation.

Check the old module
Read the label, including suffixes. Photograph the connector straight on, then show the case and mounting points. Send the engine or machine record with the photos. A similar shell cannot prove the same software or connector setup.
Quote details
Include unit condition, quantity and destination. If the label is damaged or the application is uncertain, say so. Keep the request open until the original part details agree.
Ask about programming status when the offered ECM is not clearly described.