The Siemens 3SF5874-4EA is an AS-Interface front panel module built for environments where a machine operator needs a clear, sealed interface — four illuminated pushbuttons with a wedge-base lamp socket, wired as a 4-input/4-output slave on the AS-i bus. It carries an IP65 rating, so out here in the grease it'll handle washdowns and dust without blinking. The positive-opening contacts give you the mechanical guarantee for safety circuits, even though the module itself isn't an emergency-stop device.
The 30 VDC rating matches the standard AS-i bus voltage; don't expect it to switch higher DC loads. The 54.5 mm depth and 45 mm width with a 200 mm height fit a standard 22 mm mounting hole — it'll drop into a panel cutout sized for a typical pushbutton station.