A professional who screws watch balance and balance bridge assembly to pillar plate. Places pillar plate in holding fixture, and positions balance and bridge assembly on plate securing with screws.

• Tests balance for endshake (vertical play) by gently moving balance, using tweezers, and determining from experience if shake is within acceptable limits.
• Raises bridge slightly, using tweezers, or disassembles bridge and presses down on reverse side to correct shake.
• Touches oil-filled hypodermic needle to jewel to oil lower balance jewel prior to assembling.
• Observes minute parts with aid of loupe and handles parts with tweezers.