The FESTO SMT-8M-PS-24V-K-1-M12 is a magneto-resistive proximity sensor designed for position sensing on pneumatic actuators — typically a T-slot cylinder mount. It operates on a 10-30 VDC supply and gives you the flexibility to configure the output as either PNP or NPN, normally open or normally closed, which means it can adapt to most PLC input cards without a signal converter.
The 10-30 VDC operating range covers standard 24 VDC control systems with enough headroom for voltage drop on long cable runs. The magneto-resistive sensing principle detects the piston magnet through the cylinder wall, so it works on both standard and short-stroke cylinders where a reed switch might miss the magnet. The -25 to 70°C operating temperature means it's fine on a machine in an unheated hall but not inside a paint oven or freezer tunnel.