Filter Based on Matching File Size

Is it possible to filter for files that are the same based on filesize?

For instance if I had a folder with these six files:

"File1" - 500k
"File2" - 500k
"File3" - 15k
"File4" - 15k
"File5" - 41k
"File6" - 3566k

I would want to select File1 through File4 since File1 and File2 are the same size and File3 and File4 are the same size.

Been trying to get this to work for nearly an hour but but no joy. Couldn't find anything here on the forum similiar to this.
In the past I've been sorting by size and then manually selecting the dupes but this is becoming time consuming as my file collections grow.

Any pointers or examples would be most welcome!!! Thank you!

There's a Duplicate Finder tool in Opus but it may not do exactly what you want since it can't find duplicates by size (unless you want to find by size and name, which isn't the case here). You'd have to use the MD5 Checksum option which can be slow if there's a lot of data to search.

Thank you nudel, that does the trick! In todays run it took less than 3 minutes to search through 708 PDFs totaling 4.43 gigs - compared to doing this manually, that is fantastic!

I realize Nudel's suggestion works for you, however for future reference here is a filter that could also be adapted to do this.

This particular filter selects only jpg files that are either between 10kb-20kb or 50kb-75kb