Product review (5 stars): Seems to be high quality & accurate. Unexpected Shape.
Bought it to gauge the CO2 levels in the air for mushroom mycelia.
Indoor CO2 levels seem to vary, but it always reads 300-400ppm when outdoors, so I assume it is still accurate after half a year of use. In addition to figuring out ideal mushroom ventilation rates it gives a me a  great sense of how stale the air in my house is. The temperature and humidity meters also seem pretty accurate.

I was expecting it to be more disk shaped and wall mountable. However it is shaped more like a half sphere that is sits on a desk. I had it suspended in an onion bag in my mushroom chamber and that worked fine for me.