• Automatic movement - no battery needed, powered by the wearer's motion • Typically features a sweeping seconds hand for a smooth visual effect • Case material: likely stainless steel or alloy (check for markings) • Band material: likely stainless steel, leather, or rubber (check for markings) • Water resistance: Varies by model, check the dial or case back • Consider service history if available for optimal performance • Check the crystal for scratches or damage