Product Features 1. arguments supporting the activities of the self-locking device equipped with a blackboard. 2. Equipped with G-type mosaic pulley, belt pouches damping to ensure smooth sliding, durable, noise ≤36dB. Structure in the middle - both sides of the divide fit sliding structure (built-in track, frame and track integrated design) basic dimensions of 4000mm × 1281mm / td> writing surface material made of high quality resin baking sheet surface, dark green, matt inner core material proof, sound-absorbing, 7 layers of high-strength corrugated board, backplane thickness ≥10mm quality rustproof galvanized steel, the thickness of the plate surface and the liner ≥0.25mm using environmentally polyol gum paste, 30 seconds or 100% cure stereotypes, no radiation, no pollution, shear strength ≥0.26MPa, temperature ≥262 °, resistance to humidity weather. Incredible luxury high strength frame materials industry electrophoresis champagne aluminum frame, size 57mm × [100mm + (100mm side sealing)], the wall thickness of 1.2mm, the inner frame size 20 mm × 37㎜. Corners materials using anti-aging, anti-fatigue, size 80mm × 80 mm wall thickness of 2 mm ABS plastic dust removal device slide the lower left two pull-out dust box for easy storage chalk cleaning foam, removable dust box cleaning . Illustrated by the four other board composed of the same size on both sides of each piece of the fixed inner and middle tablet machine (separate purchase) in parallel, the outer layer is writing two sliding panels, you can use one machine when sliding blackboards Push to expose one machine can be used on both sides, if you do not use one machine can slide the front locked blackboard pulled one machine.