DS-2DP1618ZIXS-DE/440(F0)(P4) is an improved version of DS-2DP1618ZIXS-DE/440/T2 with various improvements
Read much more about that - and everything else - on the product page for the new version: DS-2DP1618ZIXS-DE/440(F0)(P4)
We have kept the product page for DS-2DP1618ZIXS-DE/440/T2 so that you always have easy access to the documentation.