Under tube / Warning sign

When constructing the internal part of a manhole on the street, drivers and pedestrians have a difficulty recognizing warning signs at night.
This product can solve this kind of problem.
This is a design of a warning sign embedded on manhole that can inform drivers and pedestrians about the warning signs by lightening LED lights at night.
When setting up this warning sign, it can be set in minimal stages and possible of installing it in a short period of time. This warning sign is also in a structure easy for removal.