THYGIFTREE Clamp On Desk Shelf 2-Tier, Wood Shelving Unit for Office Gaming Accessories, Tabletop Book Storage Rack, Shelf for Top of Desk, BrownNo Drill Installation Dual C clamps secure to table tops ranging from 0. 6 1. 97 inches in thickness, simply hand tighten, no tools or drilling holes in the table top. Great Decoration at Home office Our desk shelf can be used upside down, it can be mounted not only above the table as usual, but also below it, maximizing its functionality to meet your needs. Two layer shelf offers spacious storage space for office supplies, books, gaming devices,etc.