Product review (3 stars): Semi-accurate but has durability issues
I find both humidity monitors I received to be fairly accurate. They're always within 1-2% of the calibrated display integrated into my dehumidifier.

Minus two stars for durability. In the middle of the night, the magnet on one of the humidity monitors failed. The monitor fell to the ground and broke into several different pieces. The floor in the room where it was being used is carpet, and the carpet pad used underneath is thicker (softer) than standard carpet pads. I was able to repair this monitor with some handy work and make it functional again, but it probably would've been done for good if it fell onto a tile or wood floor. To avoid this problem, I'd recommend using the built-in kickstand and sitting the monitor directly on a flat surface where it won't be bumped.