ERA mod was a poor attempt by freeflow to make an adjustable LPR. In theory it was a good idea but FF just didnt follow through with it. I have only seen one maybe 2 guns witht he era mod on it that actually helped it. All the others were just on for "looks" and provided no proformance upgrade. They were hard to install and setup properly and that is one reason why just about nobody has them on their guns anymore. If you can get somebody to install/setup then it should help but if not its just an extra peice of metal on your gun.