A benzine cup is a glass container with a glass lid, often found on a watchmaker’s workbench. It generally contains rectified benzine. It is used to clean components, often to prevent oxidation. To avoid scratching the components on the glass bottom of the benzine cup, watchmakers often place a cardboard backing and sometimes a wood support. The components can then be safely rubbed with a brush. They are then sometimes dried in sawdust or between two pieces of cloth. Often a blast of compressed air, sometimes given with a dust blower, is given as a final clean.