Please see the attached picture of XCSZC1 (magnet) and XCSZC7902EX (detector). You can’t currently buy these as individual parts, but you can under complete magnetic switch XCSDMC7902EX, which has a cable length of 2m and is Atex-certified in Europe. 

 

If you want a 10m cable version, the part number is XCSDMC79010EX.