I bought a hydrometer / temperature reader for a urgent need I keep reptiles and there cages kept over heating and I needed this so I would know when it does yet it doesn't send notifications like advertised and is real slow at reading the environment I put the device in a freezer to test it I left in for 5 minutes and it read 87 farhenheit I am very dissatisfied and will not buy another product for this company an would recommend for others who are considering this company