Features: 1. Free call charges. The 4G LTE door opener accepts calls from authorized numbers and performs door opening or closing on the first ring. 2. Modern door operation — no physical contact required. 3. Compatible with various applications including gates, bollards, barriers, garage doors, rolling doors, access doors, and machinery. 4. Enhanced security — uses caller ID for identification; unknown calls are automatically rejected. No remote controls needed for individual users. 5. Remote operation without distance limitations. Users can be added or removed via SMS. Specifications: Rated voltage: 12 V DC, 1 A Operating temperature: -10°C to +60°C Storage temperature: -20°C to +60°C Relative humidity: 10–90%, non-condensing 4G LTE frequency bands: B1, B3, B5, B8 Output relay rating: 6 A / 240 V AC Supports up to 999 authorized phone numbers. Two digital inputs for door sensors, motion sensors, or other compatible sensors — triggering sends an SMS alert and activates the siren. One relay output (6 A / 240 V AC) for connecting door or machine switches. Relay activation sends a confirmation SMS to the owner; this feature is user-configurable. Designed for broad compatibility across applications using the 4G LTE network. Material: Metal Color: Blue Package Contents: 1 x GSM door opener