Compact Desk Extender: This 21.7' x 9.8' shelf conveniently clamps to the edge of your desk (up to 2.8' in thickness) with simple hand tightening and holds up to 44 lbs Clamp-on Monitor Riser: The height adjustable clamp design also accommodates forward shelf positioning, allowing the platform to be used as a laptop or monitor riser for comfortable viewing angles and dual-level organization