The one I bought has both Eutech Instruments and Oakton Instruments on the Instructions. The model seems to be SaltTestr. I'm not sure if it's a good or bad one, I just liked the price. It came with 2 envelopes of the 3000 PPM calibration solution. I'm not sure how long it will go without needing to be calibrated, or how long the electrodes last. It does have replaceable electrodes, but I'm not sure if I could find a source. I haven't looked yet.