... of writing board which contorlled by circuit board.3) writing part : high quality acrylic used many many times without any scratches ... soft cloth or duster5)lifespan of leds : more than 100000hs6) spare part: markers, adaptor, duster,chain,hook,cloth and so on.7 ... the surface3. the content on the board shinning and flashing4. spare parts: markers adaptor chain duster cloth hook and so on ...