PR500-EM Mullion Prox Reader. The PR500-EM reads EM4102 cards (also known as Miro or UNIQUE 125 kHz). It has slim and compact design and blends in well in many environments. When BC-Link is used two of these readers can be installed to control entries and exits using only one door controller. An additional benefit of BC-Link is that it supports online status monitoring. Card technology: EM4102 (also known as Miro or UNIQUE 125 KHz)Card compatibility: IB41-EM, IB42-EM, IB44-EM, IB45-EM, Card read distance: Up to 10 cm.