... at design, patent number ZL200920133615.6We manufacture 5 series LED writing board as bellow:A series: This is our best selling type, with ... 1.5cm. refer to HQ338.HQ438. HQ584. HQ638. HQ855. HQ790M series: This is Multifunctional Board, with removable background, you can use ... Thickness is 2.2cm. refer to HQ550W,HQ438W.HQ584W.HQ638WT series: This is our transparent design, with aluminum frame. Writing ...