ATN's X-Sight 4k scope is a major leap in their NV scope line, but the position and knurling on the zoom knob requires two fingers to turn. In a situation where speed is paramount (like you're zooming in for that shot on a hog) being able to one finger zoom is major advantage.
This upgrade slips onto the zoom knob, and maintains a low profile so it won't get snagged when moving in brush.
They work equally well in stalk, blind or stand hunting.
Knobs can be painted using a plastic primer before final color coat.