These are used in the picture framing business to hold artwork (canvases) into frames (see diagram below) Of course they can be used in other ways like holding thick glass or wood panels behind an opening. Attaching things this way would be reversible. They measure 1/2" wide x 1" long with an offset of 1/4 in or 1/8 in. (can be hammered a little flatter if needed) Can also be flipped upside down to hold the item in as well.