Which Stylus for Dell Latitude 7275?

[ymmp]

HI,

I know that the stylus for the Dell Latitude 7275 is the PN556W (N1DNK), but I have a couple of questions:

1) Are there different versions of it (perhaps manufactured at different times). If so, how do I know that I am getting the most recent/best version? Relevant to this, I see an additional modifier on eBay "6D5GT" - what does that refer to?

2) How does the Huawei Mate Pen compare? Are all its buttons functional?

Thanks!