Can't figure out difference between ultrawide monitors!?

[brisa117]

So I'm thinking about getting an ultrawide 21:9 monitor. During my research, I've found several models of 25" monitors from LG with slightly different model numbers and no differences that I can tell. Anyone know the difference between these three LG monitors: 25UM64-S, 25UM65-P, and 25UM55-P. There has to be some differences to support the pricing (and even existence) of these three screens. Thanks in advance!

 

[digitaldoc]

The resolution is the same between the three of them.

25UM64-S: $290

LG 25UM65-P: available as a refurb for $219, so I am guessing that this was a previous model, and not the current one

LG 25UM55-P: $249, and high glossy screen