I bought one from smog, the yellow black housing with key switch
this is why....
In the netherlands a simular switch from moeller cost you about 70,00 euro incl keys, housing and contacts.
http://shop.rexel.nl/moeller-noodsto...mation.raction
Smog offers a housing a key and 1xNO & 2xNC switches for 30,00 euro incl shipping.