This is the regular V-Core 3 rear motor mount with a sealing lip and minor adjustments.
The sealing lip is on top of the bottom panel and therefore both seals and additionally underpins the motor mount.
It is designed for a 3mm bottom panel and will not fit anything else.
Source: https://github.com/Rat-Rig/V-core-3/blob/1.0.3/cad/printed_parts/essentials/step/lead_screw_motor_cage_back.step
The author remixed this model.