2 pieces multi-dimention green board and white boa

green board and white board 1It compound contains two green boards which can be moved to all directions:up and down, left and right or inclined. 2)One white board is set in the middle.when the white board is not used,the green boards can be moved to the center,or moved to any position that the teacher wants. 3)To ues the white board,just move away the green boards which are on top. 4)The white board can be used for both projection or written. 5)The up and down structure adopts the synchronized up&down axletree,the move dimension is 1000mm-1200mm.