Napco Starlink2 SLe-GSM Two Universal back-up or primary GSM alarm communicators.SLe-GSM Series Features:Universal full event reporting from any panel virtually anywhere to any Central Station (No radio activation fee. No special equipment.)Compatible with control panels that communicate using Contact ID and 4/2 formatTwo Models: Original SLE-GSM or SLE-GSM-3/4G 3G/4G Network-CompatibleFull High-Speed Napco Panel remote uploading/downloading (2-way communications, requires high-speed cable)Signal-Boost Technology amplifies alarm signals and wave shapes for unprecedented reliability even in remote/fringe areasEmail/Text/SMS messages alerts, selectable option (SLe-SMS service).1-Step enrollment and programming built in, ready for most jobs. (Advanced programming options also available.)Automatic dialer-capture technology eliminates time-consuming web setup!Takeover Feature – Easily captures any panels existing CS phone number and allows you to reroute it to another central station.Remote arm/disarm any panel brand with a keyswitch input (SLe-REMOTE selectable service option). Free App.New StarLink Full Data wireless alarm communicatorClick and drag to moveFor backup radio mode supervises telco and only sends GSM reports when its not functioningFuture-Proof Field-Upgradeable Communications Technology – The only alarm communicator in the category that is plug-in field upgradeable to conform to progressions in network technology — to move to the latest eg., 2G, 3G,5xG, etc. (See ordering info for field upgrade kit and choice of radio models.)Includes SIM card and dual band high-efficiency antennaOptional Smart Charger Module for use when panel aux power is at a premium and/or for optimized radio mounting locations up to 100 from the panel (Module maybe used with or without its own 4AH/12V battery).