This Module is currently available.
Quad CV Inverter
This 2HP Eurorack module will invert 4 separate CV signals. Any positive voltage at the input will be inverted negative at the output, and vice versa.
https://reverb.com/item/73168643-mazzatron-quad-cv-inverter
Included in 8 Racks, 3 are public:
Specs are approved by the manufacturer
Mazzatron Quad CV Inverter