This Seiko 5 Sports Speed-Timer, reference number 6138-0010, is a classic chronograph from the late 1960s/early 1970s, showcasing a sporty and functional design typical of the era. The black dial features contrasting subdials for the chronograph functions, luminous hands and markers for enhanced readability, and a tachymeter scale along the outer rim. A day-date complication adds practicality, and the "Seiko" and "Speed-Timer" branding are prominently displayed, along with the "5 Sports" designation. The rotating bezel adds to its utility for timing events.

The stainless steel case and bracelet contribute to the watch's durability and classic aesthetic. An automatic movement powers the watch, combining convenience with traditional watchmaking.

This Seiko 5 Sports Speed-Timer, reference 6138-0010, is a testament to Seiko's history of producing reliable and stylish sports watches, particularly during the era of automatic chronographs.