When sourcing Seiko watches, you must distinguish between Movement Types (Automatic, Quartz, Kinetic, or Solar). For mechanical models, verify the Caliber number (e.g., 4R35, 6R35) to ensure accuracy and power reserve standards. Ensure the Crystal Material meets your market needs, typically ranging from Hardlex glass (Seiko's proprietary toughened mineral) to Sapphire crystal for premium models. Additionally, confirm the Water Resistance (WR) rating, ensuring ISO 6425 compliance for 'Diver's' labeled watches.