This is a great at-a-glance device for casual indoor air monitoring, especially after renovations or for peace of mind around furniture or paint. It's not a professional-grade tool, but for the price and simplicity, it does its job well.It arrived securely packaged, with the manual and USB-C cable included, and the display was protected with plastic film. Out of the box, it felt well-built — not hollow or cheap — and the buttons are responsive. The single top button toggles the display, while +/- on the back adjust settings easily.Setup was effortless — I charged it once, and over a month later, the battery is still full. That’s impressive. The LED display is bright and easy to read, and the unit cycles through formaldehyde concentration (HCHO), temperature, humidity, and time.It seems reasonably accurate. The temperature matches my other thermometer, and the HCHO reading reacted when placed near a freshly painted surface. It doesn’t offer logging, alarms, or app integration — just a clean, real-time readout.✅ Pros:Great battery lifeClear, readable LED displayFeels sturdy and reliableVery easy to use, no setup headachesDetects noticeable HCHO changes⚠️ Cons:Only measures HCHO — no VOCs, CO₂, or particulate matterNo smart features, alerts, or data trackingNot intended for professional use or diagnosticsIf you need a simple home formaldehyde monitor that’s easy to read and lasts forever on a charge, this one’s a winner. Just know its limits.And for what it’s worth… my cat was fed up with me sitting on the floor obsessing over it, walked over, meowed at me, and just flipped it over like it was nothing. Still works fine. Durable and cat-tested.