Features Temperature and water level display: this meter monitors the liquid depth of the tank and displays the temperature of your room, the temperature of the water tank and the water level (shown by a bar chart with 10 elements). Transmission frequency: the transmission frequency of the level sensor is 433 MHz, the transmission distance is 100 meters (300 feet) in an open area, and the transmission interval is the level change of 30 seconds or the level remains unchanged for 3 minutes INTERNAL VIEWING: Ultrasonic Water Tank Liquid Depth Water Level Sensor allows you to accurately observe your outdoor water tank in your own comfortable living room with an effective distance of up to 100 m. Easy installation: you can hang the receiver unit on the wall or pull out the bracket and place it on the kitchen worktop, table or desk. Or hang on the wall. Simultaneous display: the transmitter of the water level sensor can simultaneously display the indoor temperature (℉ or ℃) and the water tank temperature (℉ or ℃). Temperature accuracy ± 1°C Description: Keep an eye on your outdoor water tank conveniently from your own living room, up to 100 m away. Installed on top of your water tank, the transmitter unit measures the water level with an ultrasonic sensor and the temperature with a thermal sensor. Specification: Indoor temperature range: 0~60℃ Outdoor temperature range: -40~60℃ Temperature accuracy: ± 1 °C. Water level measurement range: 0~15m Resolution: 0.01 m Accuracy: +/-0.03 million Transmission frequency: 433 MHz Transmission distance: 100 meters (300 feet) in open area. Transmission interval: 30s at level change or 3 minutes at unchanged level Receiver battery: 2 x AA 1.5 V LR3 alkaline batteries (not included). Transmitter battery: 6 x AAA 1.5 V LR6 alkaline or lithium batteries (not included). Battery life: at least 12 months for receiver At least 12 months for transmitters Receiver size: 108 x 94 x 27 mm. Transmitter size: 97 x 68 x 152 mm. LCD size: 66 x 45 mm (3.3 inches). Suitable liquid type: all non-corrosive liquids Open distance: approx. 100 m / 328.1 feet. Effective distance: approx. 30 m / 98.4 feet. Package includes: 1 x water level sensor transmitter. 1 x inner receiver. 2 x screws. Batteries are not included. Note: 1. Insert the battery into the battery compartment of the transmitter, do not insert the battery compartment and insert the battery synchronously after the receiver is set up. 2. The level indicator has no data, press the tank button, and the data will be displayed. 3. After resetting, remove the battery. Wait for a while and then turn on the device to eliminate the remaining power of the device.4. Whether the red light of the transmitter flashes, the flashing is normal and vice versa. Package List