The present invention relates to an electromagnetic vibrator of variable reluctance type, according to a new principle which provides higher efficiency, smaller dimension, and higher reliability compared to known technology. The assembly includes an inner tubular collar having one end insertable in one end section of a first chimney component and an opposite end insertable in one end section of a second chimney component. The base station determines whether the first terminal apparatus and the second terminal apparatus conform to a condition. The first conductor of the electrical connector section of the first connector unit and the second conductor of the second connector unit are electrically connected to each other when the electrical connector section of the first connector unit and the second connector unit are connected to each other by use of their electrical connector structures.