This delicate process involves disassembling and examining up to 300 parts under a loupe. The parts are inspected, cleaned, or replaced before being reassembled, which can take up to 10 days. The service includes battery replacement, light buffing and water pressure testing if needed. For mechanical models, maintenance includes cleaning and oiling the escapement and balance, checking movement parameters and other functions. Quartz models have fewer moving parts but require battery replacement and routine movement check and adjustment. All watches undergo cleaning of the case and metal bracelet, seal replacement and waterproofing check.