The Bluelab pH Meter is a simple, reliable pH meter that provides accurate readings and unparalleled ease of use. Growers can use this AAA-battery-powered portable meter anytime, anywhere with its simple push-button pH calibration. Its auto-off function extends battery life, and its large display makes it a breeze to read. This meter includes a double-junction pH probe, pH calibration solutions, two AAA batteries and a five-year guarantee on the meter, six months on the probe. Replacement probe BCM505 is compatible with this meter.