The fixing of the glass on the hat is very rustic: dismantle and access the on / off button or batteries, must be forced to turn the hat and this can break the two plastic tabs that secure the cap mechanism to glass ... And here it is ... damn glass can not hold (a lamp to 4 ...). This very robust attachment is a shame because these lamps have a very nice lighting effect accentuated by the glass window appearance: 2 lens colors: red and blue, the LED is fixed and white ... To have been ordered to other nearly identical, I see that we can find these lamps at different merchants but the fixtures can be finally different: if the rod and the glass remains the same, the hat and fastening system can change ... So, robustness level, it's a little lottery ... the models I had were better designed mechanically ...