The MaxSonar-EZ1 from Maxbotix, Tucson, AZ, is a sonar range finder capable of detecting objects from 6 in. to 254 in. with 1 in. resolution. Objects from 0–6 in. range as 6 in. The device features continuously variable gain for beam control and side-lobe suppression, reading rate of up to 20 Hz, triggered and free-run operation, and 42 kHz sensor operation. The range finder provides simultaneous pulse width, analog voltage, and serial digital outputs.