The ACM26-EM is an economy mullion mounted 125 Khz proximity card reader for direct mounting to door frames.  Reads 125Khz EM cards and reports both a facility code and card ID number as a 26-bit Weigand output. This unit has a bi-color LED but does not have a LED control line. The LED always is illuminated bright red until a valid card is used, which causes the LED to turn green, briefly.  Includes a buzzer input control line for on board piezo buzzer. Has an "alien metallic blue" plastic cover. Grounding the purple control wire causes the output to change from 26 bit to 34 bit.  Potted electronics allow this reader to be used on external applications.  Be careful when removing the snap-on cover for the installation, as the LED is somewhat fragile and can get damaged when removing the cover. 

These readers require a door controller to function.