Regarding the optional ELK-M1PR prox reader which mounts into the M1KP keypad, what is it's read range and where does the antenna mount?
The read range is approximately 1 cm (~3/8") from the face of the keypad. The antenna is built into the reader package which is about the size of 6 quarters stacked up. The reader is invisible from the keypad front.
In lieu of the M1PR, an external prox reader (26 bit Weigand format) can be connected to the keypad.