Review on ✏️ Adjustable Circle Drawing Tool - Aluminum Alloy Circle Template Maker for Drafting, 125 mm - Includes Black Flannelette Bag - Round Circle Template Tool - Ring Circle Making Tool (Yellow) by Kristen Simpson

As mentioned, they break easily. Two screws must be loosened to open/close the panel. Since the bezel is not that easy to close, the screws have to be loosened slightly. The problem is that it's two screws that also hold the whole assembly together! If they are loosened too much, the individual blades can slip off the small retaining lugs and damage the device. If it was designed so that an extra set of screws would hold the knot together enough that the blades wouldn't move, it would be MUCH more useful.