Newmar 25 Amp Noise Filter I have two filters at $40 each, which is less than 1/2 price. Filter reduces interference generated by alternators, ignition systems, and motors in GPS, depth sounders, radios, and stereos. Specialized models filter either noise source or affected equipment. Singular or multiple filters can be applied,... Contact Info: djk5753@yahoo.com (207) 229-8496 Location: Biddeford it's NOT ok to contact this poster with services or other commercial interests maine