CRL Set Screw Glass Clamps are designed for smaller glass mounting projects. They are an economical way of attaching shelves to walls. These solid brass clamps can be used for a variety of glass applications. It is recommended that these clamps be attached into wall studs or a wood substrate using CRL Cat. No. 8X112FHPSMS Flat Head Phillips Screws (sold separately), and a plastic tipped set screw secures the glass. They can be installed without drilling holes in the glass.