Our Review: SCSI Probe is a vital utility if you have additional SCSI devices (such as scanners or hard drives) attached to your Mac. SCSI Probe will search for attached devices and allow you to mount those which did not mount at startup. Essentially that's all it does - but that small task is essential if you wish to use SCSI devices. SCSI Probe can also be set to attempt to load devices at system startup so that you shouldn't even need to run the utility! Small and essential - a must for Mac users.