Several instances of custom component

Hi all. Newbie here. Not yet friends with the config syntax.

If I have a custom component that I would use as

foo:
  entity_id: myscene

How would i write if I want another instance?
I assume I can’t have another ‘root’ entry called foo: again.
In reality I have found a alarm clock component, and I want several separately controlled alarms. My actual config is this:

alarm_clock:
  time:  sensor.alarm_time
  master_control: input_boolean.alarm_clock
  entity_id: scene.uteOn
  additional:
    time: 7200
    entity_id: scene.uteOff

Thanks in advance.