Possessor of a V3 inforad I wished acquire this INFORAD V4 + support battery to avoid having the wire antenna bumper athermal windscreen and the power cord to the cigar lighter. easy to install, highly efficient, light and sound signals to the right level. One downside: after each use disconnect it from its battery does not support the position vider.Il should be a "stop" or by a small switch is on the control dial. Otherwise AMAZON very effective Service Delivery and Returns sav nothing to say.