Feature: 1. Support Voice Service: Use this terminal to connect with ordinary wired desk phone and standard SIM card to make local, domestic and international calls. 2. Reverse Polarity Signal: GSM desktop caller with reverse polarity signal, can be connected to a billing device or use a computer billing device. 3. Multi Group IP Setting: Fully automatic IP function, multi group IP setting, using GSM 4G cell phone SIM card, without changing the original dialing habit, easy to use. 4. Strong Signal Reception: GSM ID dialer is easy to install, simple to operate, strong signal reception, clear call setting, long service life and stable performance. 5. Widely Used: GSM caller is widely used in remote villages, mountainous areas, houses with weak signals, public telephone stores, offices, telemarketing, ships, trains and other mobile places. Specification: Item Type: Fixed Wireless Terminal Material: ABS Installation: No need to invest in ground wired line, support 4G/GSM cell phone SIM card. Easy installation Voice Services: Support International and Domestic, Local, Fixed/Mobile Voice Services Operation: Do Not Change the Original Dialing Habits, and the Operation Habits of Ordinary Telephone Landlines Are the Same Antipodal Signal: With Antipodal Signal, Can Be Connected to the Fare Register or Use a Computer Fare Register. Watchdog: Inbuilt Watchdog Circuit on Duty. Automatically Detects the Running Status of the Device, and Restarts Automatically when a Fault Occurs No Error: DTMF Transmission Mode, the Caller ID Error is 0 IP Function: Automatic IP Function, Multiple Groups of IP Settings Calling Party: Calling Party IP Prefix of Fixed Long Distance Calling, Such As 17951, 17911, and 193, etc. Permission Setting: Permission Setting of Incoming Call of International, National, and Local Calls Code Preset: Preset Local Area Code, Local Number Segment, and Forbidden Number or Number Segment Encryption Settings: Such As PIN, PUK Encryption Machine Card Locking Function LED Lights: Display Signal, Standby State, Working State and Other Information Caller ID: Yes Interface form: RJ11 TDD: B38/B40/B41 WCDMA: B1/B8 GSM: B3/B8 EC25 AF: LTE FDD: B2/B4/B5/B12/B13/B14/B66/B71 WCDMA: B2/B4/B5 LTE FDD: B1/B2/B3/B4/B5/B7/B8/B28 LTE TDD: B40 WCDMA: B1/B2/B5/B8 GSM: B2/B3/B5/B8 Recording Function: None Signal Sensitivity: <-104DBM Transmit Power: <2W Antenna Power: >1.5db Power Supply: 5V 1A Equipment Power: <5W RJ11 Dial Tone Frequency: 450HZ RJ11 Feed Current: 20MA to 40mA RJ11 Reversed Polarity: Supported RJ11 Call: DTMF Working Environment Temperature: Minus 20℃ to 50℃ Operating Environment Relative Humidity: 10 to 90% Product Size: L x W, Approx. 15.5 x 10cm / 6.1 x 3.9in ( Manual Measurement, Slight Error May Exist ). Package List: 1 x Fixed Wireless Terminal1 x Power Plug1 x Antenna1 x Antenna Receiver1 x Phone Line1 x User Manual