What is a Seiko mod?

A Seiko Mod is a custom-built watch created by upgrading a genuine Seiko-powered timepiece with carefully selected aftermarket components. At Blank Mods, we design and assemble each watch from the ground up, combining reliable Japanese movements with distinctive design and craftsmanship.

Our builds are powered by trusted Seiko TMI movements, including both automatic and meca-quartz chronograph calibers such as NH35, NH34, NH38, NH71, and VK63/VK64.

NH35 – A durable automatic movement known for its reliability and strong everyday performance.
NH34 – Features a GMT complication, allowing you to track multiple time zones.
NH38 – A no-date automatic movement that creates a clean, symmetrical dial design.
NH71 – An open-heart movement that reveals part of the watch’s internal mechanics through the dial.
VK63 / VK64 – Meca-quartz chronograph movements that deliver quartz precision with the sweeping action and tactile feel of a mechanical chronograph.

The NH-series automatic movements are self-winding, powered by the natural motion of your wrist, and offer around 41 hours of power reserve. The VK-series meca-quartz movements run on a battery while replicating the look and feel of a traditional mechanical chronograph, combining convenience with classic watchmaking style.

Each Blank Mods build uses premium materials including 316L or 904L stainless steel cases for durability and corrosion resistance, along with sapphire crystal for exceptional scratch resistance and clarity.

Every watch can be fully customized, allowing you to choose elements such as the bezel, dial, hands, case finish, and strap. We also work with high-quality dial manufacturers and offer options for custom logos and unique dial finishes, making each piece truly personal.

Whether you’re an experienced watch collector or exploring your first custom timepiece, a Seiko Mod offers the chance to own a watch that blends reliable engineering with individual style.

At its core, a Seiko Mod is more than just a watch — it’s a hand-assembled timepiece built to stand out and made to last.