Boom! Prime finally releases its N4 lower for PTW through Noveske license holder, SOCOM Gear.
Not sure about the fire selector markings, nor the “M4” marking on the mag well. But the when fit is as good as Prime’s, you know this is set to be the definitive N4 lower. It’s certainly the only one in production right now, AFAIK.
Available from Redwolf.