Fits slatwall or gridwall. Large Universal Crystal Clear Acrylic Sign Holder. The vertical acrylic sign holder measures 8 1/2"W x 11"H. Display your sign on slatwall or gridwall using this vertical acrylic sign holder. The large acrylic gridwall sign holder hooks on to any horizontal grid or slatgrid panel wire. The acrylic slatwall sign holder hooks onto the horizontal slatwall groove. Palay Display has a wide selection of vertical sign holders for slatwall and gridwall. In stock.