The Siemens 3RG4613-3AB01 is an inductive proximity switch in a 12 mm flush-mount cylindrical housing, with a PNP output. It detects the presence of ferrous and non-ferrous metal targets without contact, switching a DC load when the target enters the sensing field.
The 12 mm flush-mount body fits standard 12 mm mounting holes and sits flush with the mounting surface, which reduces the sensing distance compared to a non-flush version but allows installation in confined spaces. The PNP output (sourcing) is compatible with most PLC digital inputs that expect a positive voltage signal. DC operation means it requires a DC power supply, typically 10–30 VDC for this class of sensor.