to the transmitter housing body 1 by three webs 18 arranged at an angle of 90 u00b0 to one another this strip 17 again having a toothed portion 19 at one of the ends thereof and at the other end thereof a head 20 which is provided with an orifice 21 for the passage and anchoring of the toothed end 19 when the strip is fastened to the nozzle 6 of the lye runoff bellows 7 of the tub during the assembly of the transmitter housing body 1 the latter is slipped in this manner onto the nozzle 6 of the lye runoff bellows 7 until the nozzle 6 abuts the webs 18 and thereafter is affixed with the clip 4 by anchoring the toothed end 19 in the head 20 of the fastening clip 17 furthermore the clamp 5 is also distinguished by a body which is fixedly connected radially to the transmitter housing body for this purpose the clamp 5 has a radially directed extension which has a first pair of wings 22 bent resiliently on both sides toward the free end of the clamp and having a substantially rectangular profile springing out of the concave outwardly directed middle part of the extension is a peg formed with a pair of thickenings or thickened portions 23 having a width similar to that of the orifice 15 of the anchoring projection 16 of the tub body the outwardly rounded free.