No it isn’t a true compressor. It has an internal rotating bezel and general look of one but not the pressure seal.
The strap is a nylon perlon strap from the same manufacture as the watch. The watch shipped with a rubber strap that I wasn’t a big fan of — it felt too narrow for my taste.
The perlon strap feels and looks a lot better in my opinion but I am a bit concerned about how well it will hold up.