I bought this after having a wood floor installed to monitor humidity. When it's too humid, the floor creaks. Great gadget/tool.

I needed this product now that it is winter and am using my humidifier since I can't stand to get static shock when touching metal. Appears to be very accurate and is easy to read.

Does the job In our camper. Easy to set and easy to read.

Works well. I had a mild problem in this humid area, so got these along with dehumidifiers. Also keeps temperature..I don't know which is more accurate, but each hydrometer reads a few degrees lower than what my air conditioning thermostat says.

Takes a special battery.