If I remember correctly, the household formaldehyde detector produced by this company was the one that was featured on Xinwen Network. We don’t have any offline sellers of their products locally, and I don’t know if they are available elsewhere.
A friend once bought one of their formaldehyde detectors from the "Suzhou Guoke Xingan" store on a certain website, with a formal company invoice. That store should be the company's official direct sales store.