Callout for Omron -1 Suffix in SRT2-MD16T-1

Omron Module
Is there a difference between Omron Automation Digital I/O Terminals SRT2-MD16T and SRT2-MD16T-1?

SRT2-MD16T = NPN (- common) internal I/O Circuit.
SRT2-MD16T-1 = PNP (+ common) internal I/O Circuit.

Click here for the Datasheet.