The NXT-5R measures 4.18 inches high by 2.95 inches wide by .625 inches deep (10.6 cm high x 7.5 cm wide x 1.6 cm deep) and can be mounted on a US single gang electrical box or flat on a wall. Read range is up to 6" (15cm) when mounted at least one inch off metal. If the reader is mounted using a metal electrical junction box with the thickness of the wall material separating the reader from the box, read range will be reduced.
Please note, the NetXtreme is not compatible with the Doors/PXL family of products.
Links en Español 
NXT Series Readers Data Sheet
