The PINPOINT II Calcium Monitoris the only truly affordable and accurate digital Calcium measurement instrument for marine saltwater. Powered by a 9-volt battery (not included), the PINPOINT II Calcium Monitor will operate for approximately 150 total hours before battery replacement is visually indicated on the display. The PINPOINT II Calcium Monitor now features a solid state probe for increased stability, accuracy and longer life. Calibration is fast, easy and precise. Generally used as a precision spot testing instrument with possible continuous monitoring capabilities. The PINPOINT II Calcium Monitor will precisely determine the calcium level of any marine system.