Contactless Level Sensor LC100

Tank content display in liters and percent
Non-contact measurement by ultrasonic vibration
Distance to liquid surface: 20 - 250 cm
Mounting method: top of tank, mounting thread 38.1 or 50.8 mm (1 1/2-inch or 2-inch)
Gauge-accurate result
Supply voltage 6 V/DC (4x AA battery penlite)