8-string bass and guitar hybrid

Charlie Hunter, a jazz.. guitarist? Plays one of these 8 string hybrid guitars. I guess its three bass strings and 5 guitar strings. Different pickups and different amps for both sets of strings.

Does anyone know if any company makes these or if they're all custom? I searched the web and found a couple guys that had them.

I know its not technically a bass, but when I did a search I found some guys who bought them to experiment were bassists so I thought I'd see if anyone here knew anything about it.

Thanks.