1.The ID-22 is a 9v ¨C 27v low power industrial probe reader for popular EM4001 format 125KHz tags and is encapsulated for environmental protection. 2. Low Power module, the ID-12LP that draws less than 1mA. The LP series are ideal for environmentally sensitive building applications. 3.A Micro-Power module, the ID-12uP that draws an unbelievable 5¦ÌA at 3v. 4.A Stand-alone reader module with internal memory for 48 cards, the ID-12LA-SA 5. An HID-EM Dual system Module for 125khz, the new ID-12LA-HE 6. An ISO11785 module for 134khz, the ID-12LA-ISO 7. The amazing Ix5 Anti-collision Reader that can simultaneously read up to 5 EM4001/EM4100 cards with super range, up to 100cm
http://bildr.org/2011/02/rfid-arduino
http://www.rfidexpo.net/index.html