It is an economical and easy-to-use product. You just can put in your PVC foam poster with 1/4 to 7/16 inch (5 to 10 mm) thickness and adjust the nut of fixing from the bottom part of the aluminum box. It can be used in all indoor areas such as; schools, seminars, restaurant chains, showrooms, exhibition areas, malls and everywhere else. Packed with an easy-to-understand instruction sheet. To change the poster boards, please loosen the fixing nut under the aluminum box.