I have since upgraded my alarm panel but this antenna was mounted and used indoors. As you can tell it looks new.  It worked great

Enhance your home security with this Weatherproof External 4G/LTE Cellular Antenna Kit designed for Honeywell AlarmNet. This antenna kit is perfect for those who want to ensure that their alarm system is always connected to the internet. With this kit, you can easily extend your cellular range and ensure that your alarm system is always communicating with your cellular provider.

This antenna kit is specifically designed for Honeywell AlarmNet and is easy to install. It is weatherproof, which means that it can withstand the elements and continue to function for years to come. With this kit, you can rest assured that your home security is always protected.