Equipped with productive portable electronic telephone set factory and company, Fenghuo Hongsheng is one of the leading China portable electronic telephone set manufacturers and suppliers. Welcome to contact us.Model HFDX-1 Portable Electronic Telephone Set can replace of the traditional magnetic telephone. It is specially used for the wire communication and the communication distance of is 21km. It has the advantages of water-proof, shock-proof, clear in voice, stability in operation and good compatibility performance.Main Technical Specifications:Operating temperature: -40℃～+50℃Dimensions: 50mm×110mm×240mmWeight≤1550gPower voltage: 4.5V (3 pieces of dry batteries)Tx ring frequency: 16Hz～30HzRx Sound level≥70dB (A)Amplitude≥55V (3kΩ load)Tx ring duration time: 1s～2sTransmitting characteristicsLength of Simulated User's line0Km5KmTx Loudness Evaluation Value(dB)≥5≤18Rx Loudness Evaluation Value(dB)≥-13≤2Side Tone Shielding Evaluation Value(dB)≥0≥2