Hopcd 1-Channel GSM Alarm System, GA01P GSM Mini Smart Remote Power Failure Alert SMS Call Alarm Security for Door Magnetic Switch, Infrared Sensor

I was really keen to integrate one of these units to my garage door. So i would get a notification every time it was opened, but more importantly I had a text record that i had closed it again afterwards.Worked great for the first few weeks, but now the texts are intermittent (and yes, i have credit on the SIM card). Sometimes i get the message, sometimes there is no message - so you cant rely on it to work and accurately tell you whether your gate/ door/ window is open or closed. Very disappointed