I bought this after a freezer disaster due to an RCD failure. The unit looks good in place, and displays the temperature accurately. However, it is very sensitive to sensor placement in the freezer. The suction cup is vulnerable, being easily displaced by drawer movement, and needs glueing in place for safety (don't use superglue!) Even though I now have it safely positioned, the alarm activates randomly, even though the temperature remains at -20C! As this is a rare event, and the use of glue prevents me returning the item, i can at least switch off the alarm and rely on the display. A successful, if partial answer to my freezer problem!