This holder fits all BambuLab swatches as well as the self printed ones.
The swatch size is 24mm x 24mm x 2mm.
There are two options for the holder. The "tight" one has a clearance of 0.15mm to the swatch whereas the loose one has a clearance of 0.35mm.
You can download the fusion360 file yourself and change parameters as you need: https://a360.co/477k5u1