Pentagon has been designed for great balance between modern city and environment while bringing out the flimsy feature of LED. The next generation lighting source and “Slim & Geometric” provide reliability and robustness. In terms of structure, covers of light source part and tool parts are isolated for separate opening, which not only reduces unnecessary exposure of parts, but also prevents incidental injury of installing personnel that may result from opening one huge and heavy cover. The existing die-cast aluminum body is resistant to dirt, discoloration or damage, safe and easy to recycle and therefore environmentally friendly.