Every extension that you register with vCenter Server must have a unique extension key that vCenter Server uses to identify the extension.
To ensure uniqueness, you can use the Java package-naming convention for the key value, for example com.yourcompany.yourextension. The EAM Sample Solution sets the extension key by defining the extensionKey=com.vmware.eam.sample.solution property in the eamri.properties file. The Manager.java class picks up this property by calling the Extension.setKey() method.
If you change the extension key in the extensionKey property in eamri.properties, you can see the changed name in C:\Program Files\VMware\Infrastructure\VirtualCenter Server\extensions on the vCenter Server system, or in /usr/lib/vmware-vpx/extensions/ in the vCenter Virtual Appliance (VCVA).
You can see the extensions that you register with ExtensionManager in the vCenter Managed Object Browser at https://vcenter_server_ip_address/mob/?moid=ExtensionManager