This part is a kind of semiconductor called MC340.

Function of this product has Magnetic Contact.

Manufacturers : Alarmtech

Image and pinout :

Some of the text within the PDF file :

MC 340 Instruction Manual Detectors Instruction Manual 4-MC340-01 Magnetic Contact Recessed mounting MC 340 CIRCUIT DIAGRAM DISTANCE DIAGRAM - WOOD DESCRIPTION MC 340 is a versatile magnetic contact used in both alarm and security access control systems for protection of doors, gates and windows against unauthorised opening. A wide range of accessories enables the contact to be recessed- or surface-mounted on a variety of surfaces, including ferromagnetic materials. MC 340 is certified according to EN 50131-2-6:2008. MOUNTING INSTRUCTIONS  Contact and magnet should be installed axially, corresponding to each other.  Catch-bolts on the housing enable direct installation in ф 8 mm holes in wood.  Appropriate accessory must be used for installation in ferromagnetic environment. [ ... ]

MC340 PDF Datasheet Download