The Graphtec GL840 Midi Logger is a versatile data logger designed for measuring voltage parameters. With its USB interface, this unit allows for easy connectivity and data transfer. Ideal for various applications in the fields of data acquisition and logging, this product from Graphtec is a reliable tool for accurate measurements and analysis in industrial and business settings. The included accessories ensure that users have everything they need to effectively utilize the GL840 Midi Logger for their specific needs.