There is no "cover" meaning that the top of the cylinder is opened (the dust will not be a problem except in extreme cases). I bought this lamp in winter, so I have not had time to test this theory but it will be to pay attention to insects attracted to light and / or heat sources that could venture into the cylinder.
Uses screw E14 bulbs 40 watts max.
Tested with a low-energy bulb 28W HALOGEN (28 Watts consumed 35 watts of lighting power) is perfect.
Note: In principle, people who encountered problems with this lamp are those who used energy saving light bulbs and / or inappropriate. This is what made me choose this lamp because the reliability of the product itself was not called into question but that of users = yes)