Simply choose the electrode best suited for your application, connect the phtestr BNC 10, calibrate, and measure. Change electrodes to suit your application without having to purchase another meter. Order electrodes separately. Large display and tactile keypad allow for easy calibration along with USA and NIST auto-buffer recognition. Hold function freezes reading on the display for easy recording. Additional features include valox sensor housing, self-diagnostic error messages, a battery-life indicator, and an Auto-off function to maximize battery life. What's included: protective plastic storage case, lanyard, and batteries. Customizable to your application - use with any pH electrode with a BNC connector versatility of a handheld meter at a pocket price IP67-rated protects meter from water, dust, and shock while offering chemical resistance meter floats-accidental drops into water will not result in lost or damaged meters