A Seiko Audemars Piguet (AP) Royal Oak Chronograph mod, often called a "SeikOak," is a custom timepiece that merges the iconic octagonal bezel, tapisserie (waffle) dial, and integrated bracelet of the luxury AP Royal Oak with the reliable, budget-friendly engineering of Seiko movements.These custom builds typically use the highly respected Seiko VK63 mecha-quartz movement, which provides the mechanical "snap-back" feel of a chronograph combined with the reliability and precision of a quartz battery.Typical SpecificationsCase size: 41mm to 42.5mm diameterMaterial: 316L Stainless Steel Crystal: Scratch-resistant Sapphire glassLayout: Triple-subdial chronograph layout (running seconds, 24-hour clock, and 60-minute timer.hand watch.amd 3 months used. It was gifted. Have a original box. No scratches..