The product is a new old stock (NOS) Seiko faceted crystal specifically designed for Seiko diver's watches, model 6139-6012. Made of sapphire, this crystal is of high quality and durability, perfect for protecting the dial of the watch. With its origins in Japan, this genuine Seiko crystal ensures a perfect fit and compatibility with the specified Seiko models. Ideal for watch enthusiasts looking for a replacement or upgrade for their Seiko timepieces.