These boxes are set up to make you fail, braking System is not just for erratic breaking if you are in heavy traffic which most uk roads are these days it will go against you stopping and starting with traffic flows, so basically you can't drive your car when there are other cars on the road, and doesn't matter how if a low percentage you use after 10pm even if it's an emergency you can forget it, your score does not improve as quickly as it declines, These boxes do not get any approvals from the government or DVLA they are set up to their own designs....., Be very careful!!!!!