Be Izzi is a relatively new company from the Czech Republic specializing in hobby tools. This item, the Ultimate Razor Saw, is comprised of a standard handle with a straight attachment fixture and their Ultra Smooth, 0.1mm thick razor saw blade.
This tool is actually a system, with interchangeable straight, curved or Y-shaped attachment fixtures and blades of different cutting variations - basic rough-cut blades to “Ultra Smooth” very fine toothed blades. The blades can be mounted in a number of different positions and/or angles to facilitate a variety of cutting positions or angles. The tool includes it’s own small Allen wrench tucked away at the bottom of the handle (easy to miss if you don’t know its there) to loosen and tighten the small set screws that allow for changing or adjusting the blade or attachment arm. According to the Be Izzi web site, the tool is made to be able to use a variety of cutting blades, not just those manufactured by the company.