Here's why:
* Subject: The subject is the person or thing performing the action of the verb.
* Verb: There is no verb in this sentence. It's a phrase, not a complete sentence.
* "Here" is an adverb, indicating location.
* "Device" is the noun that is being referred to.
To make it a complete sentence, you would need a verb, like:
* "Here is the device."
* "This device is here."