https://www.amazon.de/Thlevel-Thermometer-Temperatur-Luftfeuchtigkeit-K%C3%BChlschrank/dp/B07JDSHD4Z/ref=sr_1_1_sspa?crid=10EEZFJFAH2TE&keywords=hydrometer+feuchtigkeit+digital&qid=1641233305&sprefix=hydrome%2Caps%2C129&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzRkRUT1pTUlBaUjNPJmVuY3J5cHRlZElkPUEwMzQwMTEzMktKRUk0QjFLODRPUyZlbmNyeXB0ZWRBZElkPUEwODg4NTc2MTNBTEsyVzFaUDNBMSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
The author hasn't provided the model origin yet.