Just by looks, which didnt' give me very much.
It's probably parallel compression, some form of distortion (tube like warmth description from product page), compressor, limiter.
You can generate your own plugin, so to speak, by understanding the signal chain that is used.
It's not until you want to venture off into your own sound completely, is when you'll need to build boutique plug ins.
edit:
https://www.gearslutz.com/board/music-computers/89255-sony-oxford-inflator-please-demistify.html (mod edit for clarity)
google is friend
There's always going to some compensation in terms of loudness and dynamics, if you experiment with your own signal chain, you'll see what the trade off is.