Toilets and urinals remove waste to help maintain sanitary conditions within a building. They include residential and commercial models as well as specialty models for prisons and mental-health facilities. Toilet fixtures (such as tankless toilets, gravity-tank toilets, and pressure-assist toilets) are permanently installed units that connect to water lines for flushing and filling the bowl. Other toilet types (such as portable toilets and macerating toilets) operate without requiring a standard water or waste line connection. Urinals include flushable units that connect to a water supply and waterless units that rely on gravity rather than flushing to drain urine. Toilet repair parts are components such as gaskets, fittings, and flushing mechanisms for restoring function to the various types of toilets and urinals. They're often used by maintenance staff and plumbers to replace broken or worn parts.