The Swain Meter Company manufactures a DC clamp-on ammeter and a DCVG Meter used for DCVG surveying. The Swain Meter Company builds its clamp-on ammeter to be used onshore, offshore with diver and ROV and used for direct bury applications. On shore MER2 sensors used with the AM13 meter are built in sizes ranging from 2.0" ID to greater than 82" ID.