The ET collaboration is organized in Research Units (RU). 

The RU is defined in the ET by-laws:
"Research Units are groups of ET Collaboration members. By default groups belonging to the same university or a local research institution are regarded as a single Research Unit. In case of national or regional research organizations with geographically distributed sections, each local section is de ned as an independent RU. Exceptions can be agreed on by the CB with a 2/3 majority. Each RU de nes a Research Unit Leader, who is the main responsible for communicating between the Collaboration and the RU. He/she is one of the delegates of the RU on the Collaboration Board (see 3.2). If several research institutions that are members of ET are co-located and there is an aliation mechanism between them (e.g. between a university and the local section of a national or regional institute), they shall form a single RU. To be eligible for ET membership, an RU must commit at least 1.5FRTEs in its  rst year and at least 2FRTEs thereafter. [...].
The CB has the  exibility and discretion to adapt the above rules to speci c and justi ed cases. Each RU appoints a Research Unit leader who serves as the point of contact for all RU-speci c enquiries from collaboration bodies, the RU members or persons wishing to become a member of the RU."

You can fin the list of RUs here: