Have you pulled the spec sheet? With the reasonable price of other reliable anchors such as Fixe, and Powers wedge bolts, why bother? Those don't look like they're stainless, and it should be standard practice to use stainless now.
From the picture it looks shy of 3/8", plated steel, and long as fuck. If the size truly is off of 3/8", they're going to be a pain to drive all the way in and tighten to spec without it spinning, and will rust considerably in 5ish years.
As has already been said, there are many places to source affordable and reliable stainless wedges. Also unless the rock is crumbling underhand 4+ inches is way overkill.