1 double sided light box,60% thicker 2 brighter,superficial lumen 1500,long light span 3 discolour resist 4 easy to maintain Company ... years experience in manufacture advertising equipment such as metro guiding double sided light box,showcase,sign panel,display rack,booth and so on. We ... span outdoor,3 years span indoor Light source:t8 philip,over 10000h life span/cree led,over 50000h life span,both ...