Modeled in two parts, which slide over top of one another and lock into place to hold the processor securely within. This particular tray (I am making a series of these for the older processors in my collection) is for Intel Socket LGA1567 CPUs from the Xeon series circa 2010. My prints were done with Recycled Prusament PLA (the one sold in 2kg spools). Be aware of shrinkage based on your filament of choice, but I don't believe the tolerance on this one is so tight as to be a problem on most systems.