Stackable wedge shaped shims are ideal for installations, adjustments and general maintenance. Interlocking horizontal and vertical ridges keep shims in place and allow for small, precise adjustments . Made from thermoplastic polymer, they won't break down, shrink or swell in damp and humid conditions like wood shims. Tough and durable. Glue-resistant, useful as a clamping pad on angled surfaces. They work on desks, tables, file cabinets, bookshelves, countertops, appliances, set-up jigs, commercial windows, doors, concrete blocks, HVAC equipment, toilets, sinks, tubs, tooling and many other similar items.