A professional who performs any combination of following duties to insert clock and watch assemblies in cases. Responsibilities include:

• Inserts and secures crown and stem into clock and watch movements, using loupe, tweezers, screwdriver, and other jeweler's tools.
• Cleans case, using airhose, and inserts movement into case.
• Presses revolving plastic cup against crown or rubs crown against plastic strip to wind movement.
• Sets watch to specified time prior to testing.
• Secures watertight cases, using pliers, or places assembly in device that tightens case automatically.
• May remove temporary crown and stem prior to assembly, using handtools.
• May measure stem, using gauge, and file stem to specified length.
• May screw crowns onto stems.
• May test waterproof watches in air pressure and water tanks.