... Screen(Sticker): light-proof sticker,2 years span outdoor,3 years span indoor Light source:t8 philip,over 10000h life span/cree ... ,hard to be broken,turn color 2 years span outdoor,3 years span indoor Hook:inner is metal tube,outer decoration is ... ,lessen the noise when closing and protect inside from dust. outdoor/indoor directional signage for metro,airport, bus stop