The bulb seemed ok on arrival but In use it switched itself off after about an hour. When I tried to remove it the base came apart leaving 4 bare live wires hanging out of the fitting. These type of bulbs are very expensive at £6 and impossible to buy in any of the shops I've tried. As they're the only type that fits in our new house this is a nuisance so I intend to change all the bulb holders for the traditional bayonet type as those energy saving bulbs are a fraction of the price. I'm also not impressed with the light output - they claim to be equivalent to 200+ watts filament but I reckon more like100 watt.