The current fine-dust filter, VF5000, can definitely fit RIDGID wet/dry vacuums that are 5 gallons and larger. We also made them to fit even the older models.
We really recommend using the fine dust filter for picking up fine dust. The filter is for capturing debris, and using the standard one will allow debris to escape through the blower port. This would cause more mess.
For any further questions or concerns you may call customer service at the number above or you may send your email to [email protected]