The three sides of see-thru acrylic provide maximum safety and visibility and the 24" height is perfect for taller students or adults. The front panel features an 11"W x 1/2"H opening at the bottom to slide papers and other small items back and forth. The hook cutouts on the side panels easily slide into slots on the front panel for quick assembly and the included four fasteners have adhesive bottoms to keep shields in place and prevent them from sliding. No tools needed for assembly. Fasteners are not reusable and additional fasteners can be purchased separately.