Hyde Park Electronics Inc.’s new SUPERPROX Model SM300 Series extended-range
ultrasonic proximity sensor combines a miniature 12mm housing and reliable detection
of all materials at distances 6.35 (0.25 inches) to as far as 50.8mm (2.00 inches)
from the sensor face. This is 6 times further than many 30mm diameter prox sensors,
according to the manufacturer.