Features:
Frequency: 125kHz
Baud rate:: 9600bps (TTL RS232 format)
Working voltage: DC 5V (±5%)
Relative humidity: 0-95%
Working temperature: -10℃ to +70℃
Storage temperature：-20℃ to +80℃
Wiring size:46mm x 32mm x 3mm
Module size:38.5mm x 19mm x 9mm
Supported card: EM/TK 4100, EM/TK4102, EM4200 or compatible
Receiving range：20-50mm (It depends on the antenna, card and the surroundings)
Sample Code:

String comdata = "";
Void setup ()
{
PinMode (2, the OUTPUT);
PinMode (3, the OUTPUT);
DigitalWrite (2, HIGH);
DigitalWrite (3, HIGH);
Serial. The begin (9600);
}

Void loop ()
{

DigitalWrite (2, HIGH);
DigitalWrite (3, HIGH);
While (Serial. The available () > 0)
{
Comdata + = char (Serial. The read ());
Delay (2);
}
If (comdata. Length () > 0 && comdata = = "0500 addf1443")
{
While (comdata. Length () > 0)
{
DigitalWrite (3, LOW);
Delay (100);
While (Serial. The available () > 0)
{
Comdata + = char (Serial. The read ());
Delay (2);
}
Comdata = "";
}
}
Else if (comdata length () > 0)
{
While (comdata. Length () > 0)
{
DigitalWrite (2, LOW);
Delay (100);
While (Serial. The available () > 0)
{
Comdata + = char (Serial. The read ());
Delay (2);
}

Comdata = "";
}
}
}