BestOfferBuy - Lamp Adapter Converter with bulb GU10 to E14 (Electronics)
Cheap and very good finish. It's really a good product with a nice finish. The bulb fits snugly inside and not moving. Fast delivery. ps: for a deep and narrow spot, try putting in first place the bulb and screw everything into the spot.
BestOfferBuy - Lamp Adapter Converter with bulb GU10 to E14 (Electronics)
The outer diameter of the sleeve is 34 mm. Some difficulties for implementation linked to the narrow spot .... Problem solved by grinding slightly adapter.