Alarm.com 9AM-18F-MMCX 18' 3G & LTE MMCX Indoor Antenna is an 18-foot long cellular antenna with an MMCX connector for plugging in. This Alarm.com Cellula Antenna works with both LTE and 3G bands, making it very versatile. This antenna boosts cellular signals in areas where an adequate connection would be otherwise difficult or impossible to obtain. The 18-foot long cable attached to the 9AM-18F-MMCX offers the user great flexibility in choosing mounting location. However, it's important to note that the cable is fixed to the antenna, and it cannot be easily removed. The 9AM-18F-MMCX is built for use with Alarm.com Communicators, and it for indoor use only.