... photo frame,showcase,light box,exhibition booth,sign panel,sign light box,display rack,bulletin board, ... 16*10*0.15mm·Groove in the back make the back panel avoid to be not fixed with screw ... ,so we save the time.if no back groove ... thickness of back board,more flexible;Product componentback board:KT,PVC forex,MDF,aluminum composite panel/Alucobond,iron ...