A modular device for wireless communication between a transmitter and a receiver, the latter being mounted on a fastener to be worn by an animal/a human being or to be in contact therewith, comprising a string of individual separate elements or modules (210, 310), each containing at least either the PCB (213, 313), the battery (214, 314) or one or more contact points (220, 320) of same polarity respectively, said separate individual elements (210, 310) being attached to one another thanks to at least two substantially parallel flexible tubes (31, 32; 331, 332) containing said wires, so that the specific location of the modules (220, 320) containing the contact points and the order or sequence thereof in the string define an extension length for the contact points.