The Tank Alert, wireless ultrasonic water tank level indicator has a range of features: - Tank levels are continuously displayed on a small LCD Panel on the receiver, which can be located up to 200m away from the tank (240v power required for the receiver) - No wires, probes, dipsticks or floats required. This product is safe and easy to install! - As it is ultra sonic, it is suitable for all vented tanks up to 3m high The battery inside the transmitter is a 3v Lithium long life battery (10 years estimated life). The transmitter works off a frequency of 433 MHz FM Transmission. Product Dimensions: - Receiver 57mm x 60mm x 41mm - Transmitter 138mm x 70mm x 40mm. Temperature ranges (Minimum/Maximum): -10 Deg C to 60 Deg C This product is not suitable on pressurized tanks. Rain Alert, wireless tank level monitors are suitable for use with: Water tanks, Fuel Tanks and selected herbicide/pesticide tanks.