This is a touch probe for a CNC machine.  The probe consists of a set of 3D printed parts and some hardware available from McMaster Carr.  The 3D printed parts do not include threads for the fasteners so they will need to be tapped prior to assembly.  The stepped boss on the top of the probe is designed to fit into either a 1/4 or 1/2 inch collet for easy mounting on the CNC machine.  
If you need some software to put your new probe to good use check out G-Code Ripper.  It will map an existing g-code file to a probed surface.  http://www.scorchworks.com/Gcoderipper/gcoderipper.html  
A lot of the designing of this part was performed on my Android phone using ScorchCAD (While traveling or waiting for my kids to be done with practice for various activities). http://www.scorchworks.com/ScorchCAD/scorchcad.html
Instructions
After I assembled the probe I found that adding a very small amount of lithium grease to the interface between the shoulder screws and round head screws helped the probe return to the closed position…