It’s an Analog Resonant Phase Rotator, model of 1977, reworked to give a 4/6-stage phaser, three resonance feedback modes and an LFO. You can also pop an Allpass filter expansion board on the back for up to 22 stages. Here are my thoughts on the Kamieniec II.
https://xaocdevices.com/main/kamieniec2/
Buy from Signal Sounds – https://moltenmt.com/signal-kamieniec2
Buy from Perfect Circuit – https://moltenmt.com/perfect-kamieniec2