This article explains the differences between MSR part number E500356 and part number E628912

Please see the information below regarding the differences between E500356 and E628912.

Both MSR's use the same internal Magtek IntelliHead HID module, P/N: 21030006

However, they differ in physical design and how they connect to the monitor. 
The E628912 for the 1523L/1723L monitors connects with a small white header.



The E500356 MSR for the 1517L/1717L monitors connects with a standard USB cable.