I strongly wish I could tell you, I have no documentation on this and there is no model number listed on it. The grey vodavi box had model 5000-00. Googled voice mail with it.
It strongly resembles:
Vodavi Communications System Inc Digital Voice Mail DHD-04 Dolphin 303-04
https://www.ebay.com/itm/Vodavi-Com...-04-/310662414639?_trksid=p2054897.l4276 (not my posting, just a picture of what it looks like.
The box already had a serial cable attached to it.
