Modular level sensor in which the intervention point is customizable, from a minimum of about 180mm up to a maximum of 560mm (860mm), simply by cutting the stem to the desired length and fixing it to the float using the appropriate expansion fitting. The sensor also integrates, in a single code, the following fixing options; flange with 2, 3 or 6 holes, and 1” threaded connection. It can also be used in fluids polluted by ferrous particles as the magnet is in the upper part of the sensor and therefore does not come into contact with the fluid to be controlled.