Some Estech control boards or interface modules use a plus a 6-pin auxiliary connector for signals such as temperature sensing, fan control, or remote on/off. In this case, the "full download" would include interconnection diagrams between the two connectors.
The specific string in your search suggests a focus on a particular version or update: : This likely refers to Version 1.2.6 , a specific release of the Estech software. Download Full estech+schematics+12+6+download+full
Downloading... estech_schematics_12_6.enc (18% complete) Some Estech control boards or interface modules use