A highly collectible Seiko Mono Pusher Chronograph 5717-8990 from 1964 JDM, this timepiece is a significant piece of Seiko's early chronograph history. It features a rare one push chronograph function, highlighting its innovative design.

The watch showcases a clean silver dial with crisp hour markers, providing excellent legibility. Its robust stainless steel case is complemented by a functional rotating bezel, adding to its utility and classic tool watch aesthetic. This design reflects the purposeful and elegant style of 1960s chronographs.

Powering this remarkable watch is a precise 21-jewel manual wind movement, known for its reliability and smooth operation. The "Mono Pusher" mechanism simplifies chronograph control to a single button, a sophisticated feature for its time. This timepiece stands as a testament to Seiko's early leadership in chronograph development.