A light guide device, comprising a light entrance part for receiving luminous radiation from a light source placed in front of it, and a light exit part configured for emitting the luminous radiation according to a distributed illumination pattern. The device includes: a first light guide member comprising a central light transmitting portion, on an end of which the light entrance part is formed, and a support portion connected to the central light transmitting portion and arranged concentrically therewith, and—a second light guide member comprising a shaft portion removably coupled to an end of the central light transmitting portion of the first light guide member, opposite to the light entrance part, and a light distributing portion connected to the shaft portion, on which the light exit part is formed.