1. Now the lamp head is required to have dual light sources, that is to say, one light bulb of the lamp head is broken, and a spare light bulb can be used. In short, you have to have this feature;
2, the brightness is enough, there is no explicit requirement for this item, but it should be necessary;
3, can adhere to more than 12 hours is better;
4, the structure is relatively stable and durable;
5. The coal mine requires the MA mark.
