Product Description for GSM-KEY-4G Remote Control Box with Relay Switch Experience unparalleled security and convenience with the GSM-KEY-4G Remote Control Box. Designed to enhance your home and business security systems, this advanced device leverages cellular network technology to provide flexible and reliable access control. Discover the features that make this system an essential part of modern security solutions: Cellular Network-Based Security System The GSM-KEY-4G utilizes a robust cellular network, working seamlessly with caller ID to identify and authorize access. When an authorized number calls, the system recognizes the caller and automatically opens the door, ensuring secure entry. Global Connectivity with Industrial-Grade 4G Engine Equipped with a professional industrial-grade 4G engine, this system functions like a standard 4G phone, using a SIM card to receive calls. The built-in 4G module ensures compatibility with 4G, 3G, and GSM networks, allowing operation anywhere in the world. Extensive User Capacity and Security Store up to 200 authorized users in the system's memory, allowing comprehensive access management. When a call is received, the system verifies the caller's number against the stored list. It also supports a power failure alarm for rechargeable batteries, ensuring uninterrupted security. Unrestricted Remote Access Unlike traditional remote controls, the GSM-KEY-4G allows you to manage access from virtually anywhere, even from another city. This feature offers unmatched convenience, allowing you to open doors remotely without delay. Independent Relay Switches for Efficient Control Featuring two independent relay switches, the system activates the NO.1 relay switch by dialing its mobile number. It rejects the call to activate the connected device without incurring call charges, identifying authorized numbers without answering. Elevate your security infrastructure with the GSM-KEY-4G Remote Control Box, offering a perfect blend of advanced technology, global connectivity, and user-friendly operation. Whether for home or commercial use, this system ensures secure, efficient, and convenient access control, making it an indispensable asset for any security setup.