ALCON CT-73S Long Range Phone up to 15km Ideal model for farms, land owners, remote locations, emergency services, security, event organizers, industrial sites, building and construction industry, marinas, boats, outdoor use ... Below ranges are results of our test and match real life performance: Max range without line of sight from 8 to 15km. Max range in optimal conditions, with line of sight is up to 25km. Features: Power: 5W Base - 3W Handset (5W Turbo) Handset Turbo power mode 5W by switch button for better reception in critical environment Works on any PSTN phone line or on analog extensions from PBX or VOIP, GSM, FXS Gateways No software setup / easy for installation Reliable and simple to use Line of sight (LOS) is not necessary for range Multi-Handset system (Up to 4 handsets) Intercom between base and handsets Hold music 40-channels Frequency auto scan when Handset turns on Handset scramble function Last number redial for Handset Backlight on handset keypad Touch any key answer function for handset 12-number memory for each handset ( 15 digits ) Handset Low battery indication Built-in noise cancellation circuit ( Compander ) 2 pcs lithium battery 10,8V 920mAh 10Wa Battery - Standard by : 60 hours, Talking time: 45~60 minutes Separate battery charger Carry case for Handset Hands-free headset (Optional), via standard 2,5mm jack Car Accessory kit (Optional) Handset Dimensions : 15cm x 5cm x 2cm (with out antenna) Handset weight : 250g with battery Security: Multiple Channel Access: 40 channels automatic scan to avoid interference Built-in voice security circuit (Scrambler). Works on two frequencies : 382.100 MHz / 256.100 MHz