Intelligent non-contact liquid level sensor uses advanced signal processing technology and high-speed signal processing chip to break the influence of container wall thickness and achieve a true non-level Contact detection. Non-contact liquid level sensor is not afraid of affecting water quality, does not need regular cleaning, long service life The liquid level sensor can detect the level of various toxic substances, strong acids, strong alkalis and various liquids in high-pressure closed containers, has no special requirements on the material of the liquid medium and the cont The liquid level sensor has instruction, please find on the product information. Brown wire : VCC(DC 5-12V connects power positive) Yellow wire:OUT( signal output) Blue wire: GND(connects power negative) Black wire:M(mode of NO/NC), Manufacturer: Esooho