These checkpoint files are Illustrious model checkpoint downloaded from CivitAI.
All credits go to their respective authors:
1. iLustMix v8.0 by GZees
2. Illustrious Realism by klaabu by klaabu
3. Ri-mix - [PONY + Illustrious] by phinjo
4. Illustrij v17 by reijlita