Maxbotix XL-MaxSonar-AE2 Sonar Range Finder MB1320

This ultrasonic (sonar) range finder features real-time automatic calibration and noise rejection resulting in virtually noise-free distance readings even in environments with changing acoustic and electrical noise. The sensor detects objects from 0 to 7.65 m (25 ft) and has a resolution of 1 cm (0.4") for distances beyond 20 cm (8"). The XL-MaxSonar works from 3.3 to 5V and peaks at only 0.5 W of power consumption.