2 bar spotlight switch?!

[johny]

Hello all. I've bought a 2 bar spotlight and noticed there's a switch on the side of it that says 43.409. I'm new to electrics and probably won't fit it myself ( me scaredy cat! ) but was wondering what that switch does as there's no reference to it in any of the accompanying leaflets and instructions. Anyone know?

[sparx]

probably there in case you use it as walllight just leave it in on position if fitted as ceiling light