* Identification Transponder in Plastic Brick Package
* Compatible ATA5557, ATA5567.
* Includes Ferrite Coil and Capacitor for Tuned Circuit Antenna 
* Basic Component: Atmel  ®   ATA5577M1330C IDIC  ® 
* Contactless Power Supply 
* Contactless Downlink Data Transmission 
* Radio Frequency fRF  = 125kHz 
* 363-bit EEPROM Memory in Total: 11 Blocks ×  (32 Bits + 1 Lock-Bit)
* 7 × 32 Bits EEPROM User Memory Including 32-bit Password Memory 
* 2 × 32 Bits Unique ID 
* 1 × 32-bit Option Register in EEPROM to Set Up the Analog Front End: 
* Clock Detection Level 
* Gap Detection Level 
* Improved Downlink Timing 
* Clamp Voltage 
* Modulation Voltage 
* Soft Modulation Switching 
* Write Damping like the Atmel T5557/ATA5567 or with Resistor 
* Downlink Protocol 
* 1 x 32-bit Configuration Register in EEPROM to Set Up: 
* Data Rate: 
* RF/2 to RF/128, Binary Selectable or 
* Fixed Basic Mode Rates 
* Modulation/Coding: 
* ASK, FSK, PSK, Manchester, Bi-phase, NRZ 
* Other Options:
* Password Mode 
* Max Block Feature 
* Direct Access Mode 
* Sequence Terminator(s) 
* Block-wise Write Protection (Lock Bit) 
* Answer-On-Request (AOR) Mode 
* Inverse Data Output 
* Disable Test Mode Access 
* Fast Downlink (~6Kbits/s vs. ~3Kbits/s) 
* OTP Functionality 
* Init Delay (~67ms)

Many Mifare card organizations today are preferring to create their particular proximity cards in-house than outsourcing it as it saves a lot of cash and may also cause certain problems like late shipment or wrong names on cards. All you need can be a badge printer and voila! They are able to make their unique cards. Hence it is easier and a lot cheaper to generate prepaid credit cards in one's own company since proximity cards are making it big time inside the security process. The badge printer can be not too expensive these days. However certain companies are still using ID cards and so are happy with to too. But ultimately these are expected to realize the need for proximity cards and shift to getting these.