... display, you can edit and erase your artwork at any time and it can even be written ... 1.For advertising to promote new items or reduction sales at dressing shops, bookstores, bars, malls, supermarket, window display ... frame with black backboard to make it as work of arts2.Easy writing and erasing---Board sheet ... ---2x3.6V 1800Ma li-battery can make board work at least 2 hours when power off5.More energy ...