... info We have 10 years experience in manufacture advertising equipment such as exterior light box,showcase,sign panel,display ... /discolour resistance,7 years long span Screen(Sticker): light-proof sticker,2 years span outdoor,3 years span ... span/cree led,over 50000h life span,both brightness of them are over 1500 lumen on the advertising/ ... and protect inside from dust. popular item of exterior light box