Device : RFID Read Only 125Khz Module
Model : RFR-300
Frequency : 125 KHz
Specification : Reading Distance 0~7 Cm , Card Type EM/TK4100/02 , Baud Rate 9600(Default) , Interface TTL/RS232
About RFR-300
RFR-300 is a small RFID 125KHz card reader module. There is an antenna inside the module can read cards up to 5 Cm.
This module has some pins for connecting Buzzer, Power LED, Read Card LED, Outside Antenna. RFR-300 can use of 2 communication protocol for sending card data : Serial Communication Output ASCII code of card number and PS2 Communication Output card number as PS2 mode.
RFR-300 module size is less than 4 centimeter that will help you make many applications such as : Time attendance machine, Access Control Devices, Goods Tracking, Loyalty Program Devices, Membership Management Devices, Electronic Door Lock Key and etc.
 Download PDF Document of RFR-300
Voltage  5VDC (± 5%) 
Current  30mA 
Frequency of Card Type 125 KHz
Reading Distance (Internal Antenna)  0~5 Cm 
Reading Distance (External  Antenna)   0~10 Cm (External Antenna Inductance: L=345uH)
Interface  RS232(TTL), PS2 
Baud Rate 9600BPS 
Temperature   Work: 0°C~ + 60°C Reserve: -20°C ~ + 60°C 
Humidity Work: 20 %~ 90% RH Reserve:5% ~ 95% RH 
Dimension 39mm X 21mm X 11.6mm