Adjusters are parts that use the properties of screws to enable height alignment in tools such as work benches and machine tools. A number of different adjuster types are available, such as the standard adjusting bolt type and mount type. Another example is the swivel-head type, which comes with an angle-adjustment feature that enables level installation of equipment on floors with non-level surfaces or the like. Adjusters are usually made of steel or stainless steel. There are types that also use various other materials such as conductive rubber or non-migrating rubber on the bottom surface to provide properties such as resistance to oil, impacts or vibrations. The proper type for the operating environment should be selected.