Dustproof and waterproof ET-538 can withstand long-term immersion under pressure, and put it into 1 meter deep water for a long time. The time can be up to 1 hour without damaging the radio. Long distance transmission ET-538 adopts long antenna design, which effectively improves the transmission intensity and the signal effect is better 4 groups, 128 channels 4 groups, each group can add channels. Built-in LED display Built-in LED display, you can intuitively observe each set value (channel, volume, power). Emergency button The distant companion's radio receives the alarm sound from the distressed person, and the general  position of the distressed person can be roughly judged according to the sound strength for rescue. Standard package  ET-538 radio*1  3800mAh Battery*1  Power adapter*1  Charger*1  Back clip*1  English Manual*1 Functions  Waterproof and dustproof  Channel Monitor   High/Low Power  Time-out timer (TOT)  Busy channel lock (BCL)  Voice Operated Transmit(VOX)  Battery saving function  Low battery warning  Emergency  alarm function  ANI Code  Programming password Specifications       General        Frequency    VHF:136~174MHz UHF:400~470MHz        Channel Capacity    UHF: 128 / VHF: 16        Operating Temperature    -20℃~60℃        Operating Voltage    DC 7.5V +10%        Frequency Stability    ±2.5ppm        Dimension    130*60*39 mm(Not include the antenna)        Weight    Approx 300g        Battery Capacity    3800mAh        Protection Grade    IP68        Transmitter        Carrier output power    UHF:12W / VHF: 5W        Modulation    16KθF3E / 11KθF3E        Maximum Frequency offset    ≤5KHz / ≤2.5KHz        Audio distortion    ≤5%        Modulation characteristic    ±3dB        Adjacent channel power    ≥65dB        Occupied bandwidth    ≤16KHz        Receiver        Receive Sensitivity    12dB  (SINAD) 0.25μV        Audio Power    1W@10%        Audio distortion    <10%        Audio response    ±3dB        Intermediation    ≥55dB        Adjacent Channel Selectivity    ≥65dB, ≥60dB        Spurious response immunity    >50        Blocking characteristics    ≥84dB