PARALAN SD16B SCSI SE to Differential SCSI Converter.  Used in excellent condition, very clean with only minor external wear. 

The SD16 Converts Between SE SCSI and Differential SCSI.

Plug a single-ended SE cable into one end of the converter and the differential SCSI (HVD) cable into the other end and the Paralan SD16B converts the signal making communication between both types of devices possible. No hardware or softwar changes are required - the converter is universal to all devices. Connector size: HD68