The adaptor plates allow you to mount the Vevor casters (2 inch, GD60FD) to your RatRig V-Core 4 500. They allow for clearance on the front Z stepper motors. I used an M8 to M6 sleeve reducing nut to screw into the M8 threads on the corner RatRig extrusions and M6 Flat Head Hex Socket Cap Screws Bolts (1-6mm, 2-35mm, and 1-40mm for the corner sleeve nut).
https://www.amazon.ca/dp/B0CHMTJ5TS?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
https://www.amazon.ca/dp/B0CH8HNTB6?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
https://www.amazon.ca/dp/B0DCYD3M42?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
The author marked this model as their own original creation.