Hi, this is Square Scriber, and it is designed for scribing up to 25mm for carpentry and woodworking. Square Scriber is perfect for scribing architraves on the door frame or marking the door latch on the front of the door. There are many ways you can use this Square, and it is handy and very easy to set up. You will need M5 nut which is part of the knob and need to be inserted during 3d printing. You will need M5 hex head screw with length of 16mm which will be inserted at the bottom of the first panel. Unfortunately I wasn't able to add any sort of measuring marking on top of the plate