It's just rescaled from the original model from 3D_Workspace to fit the new SUNLU spools.
If you want to do it for your custom spools, measure the diameter and depth from your spool, search for the nearest fit from 3D_Workspace. If you need to scale up choose the small version with 1mm holes, if you need to scale down choose the normal versiom with 2mm holes (Silica-Gel is typically between 2-5mm). Afterwards you can scale box and lid simultainusly to your new size.
Here I used the 50mm / 50g version (52mm high):
The author remixed this model.
Resized for the new spools of SUNLU spools. Model from 3D_Workspace and idea from Deadius.