The case of the Sun Ultra 20 workstation uses a propietary HD holder that allows easy HD extraction. Unfortunately, this HD holder is not available for 2.5" hard disks. As this HD format is becoming more common due to the SSD disks, I created this holder that will fit in you Sun Ultra Case. I include the STL file for printing and the Freecad source in case you want to modify it.Print and put a 2.5" hard disk inside. The screws in the external side of the holder should have a countersunk head and maybe you have to file them. Otherwise the holder could not enter in the HD bay.