Two-stage surge protection for three or four signals of floating signal circuits in the screw-on module with IP67 degree of protection for sensor heads, connection: M20 x 1.5. Tested in accordance with the following types of protection in Ex areas: Ex d/Ex tD/Ex ia IIC/Ex iaD. Suitable for use in the fieldbus system in accordance with the FISCO concept, HART-compatible. Can be used in safety-related circuits up to SIL 3.