The 2 guys that are Kalium Strings are both bass luthiers and are rebranding their designs as Kalium Guitar Works, to join the other Kalium sub-brands Kalium Electronics, Kalium Sound and Kalium Strings.
This one is of course the Quake bass of the former Knuckle Guitar Works. This is part of a production run of 5 bolt-on 5 string Quakes that will be cheaper than the former custom quakes. 4 are not claimed yet.
The post on the Knuckle Guitar Works FB page:
"I'm jumping in . . . .
Production Quakes are a thing. 4 initial variants, and all of them 5 strings; parallel Jazz and Humbucking, and fanned Jazz and Humbucking. This one will be emerald green and will live with my business partner.
I have 4 unfinished basses in the queue - anyone interested?"
The other half of Knuckle Guitar Works is the former APC Instruments, and will include this design, the 'Churchill':