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                         The fittings and the bulb holders look identical to the type we have in our k******-bought from Lidl here in France. 
The bulb end fitting type GU10 can be a halogen bulb or an led bulb -any bulb with a GU10  base will fit.  
I have no idea what energy class C or D means. 
We had halogen bulbs in the fittings, we now have Philips led bulbs, the 5 watt 36 degree beam spread are easily the equal of the 50 watt halogens, and they don't radiate any heat unlike the halogens and the power saving is just a matter of doing the maths.  
10 halogens at 50 watt each  = 500 watt 
10 leds at 5 watts each = 50 watts 
                            
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