I really like this as well, I've never seen something quite like it, the rubber on it is quite robust.
I like it a lot, it's made really well, the markings has this sort off anti glare on it, it really is precisely made, it's solid.
Much better than the standard model that shipped with the rails improving accuracy and better eliminating play.
If not, they should be the standard they ship with their rails and not have to pay more to upgrade to these, especially when having to pay US import duties twice.