These drives were installed in a DEC InfoServer (which was a networkable CD-ROM tower) that had been sitting in it's sealed box since the mid/late 90's. I tested this (and all) CD-ROM drives I sell, because I've found that is generally a good thing to do when dealing with NOS hardware from 20+ years ago. I prefer to sell tested known good items. I really like the action of these drives, including the neat servo sounds it makes before popping open the tray to be pulled out. It doesn't slide all the way out like the cheaper "coffee cup holder" style CD-ROMs of the era. These have a thinner inner height, locking ball bearings on the spindle and seem to generally have a more solid build vs. your average 90's CD-ROM. Thank you for stopping by. Have a great day!