Seiko 5 Blacktone Redux SRPK99K1 / 4R36-16D0 (2024)

Model History:
The Seiko 5 Sports Blacktone Redux SRPK99K1 is a modern automatic sports watch from Seiko’s current 5 Sports line. Released in 2024, it belongs to the Redux series, a collection that reinterprets earlier Seiko 5 Sports design language with contemporary construction, modern proportions, and the reliable 4R36 automatic movement. This model is visually inspired by the well-known Seiko 5 Sports “Fifty-Five Fathoms” style, especially the earlier SNZH-series aesthetic, with its domed crystal, bold rotating bezel, applied markers, and polished/brushed stainless steel case. The Blacktone Redux version gives the design a more refined and dress-sport character, combining a glossy black dial with gold-tone details, broad luminous hands, and a black-and-gold bezel insert.
The watch is powered by Seiko’s 4R36 automatic calibre, a modern 24-jewel movement with automatic winding, hand-winding capability, hacking seconds, and a practical bilingual day-date display. With its display caseback, and robust stainless steel bracelet, the SRPK99K1 is a strong modern everyday Seiko with vintage-inspired character.

Specifications:
• Brand: Seiko
• Model: Seiko 5 Blacktone Redux
• Collection: Seiko 5 Sports / SKX series
• Reference number: SRPK99K1 / 4R36-16D0
• Serial number: 430972
• Production date: March 2024
• Movement: Seiko 4R36 automatic
• Jewels: 24 jewels
• Functions: Hours, minutes, central seconds, day-date display
• Winding: Automatic with hand-winding function
• Hacking seconds: Yes
• Day wheel: English and Kanji
• Case material: Stainless steel
• Case diameter: Approx. 42.5 mm without crown
• Lug-to-lug: Approx. 46 mm
• Case thickness: Approx. 14.2 mm
• Dial: Black dial with gold-tone accents
• Crystal: Original curved Hardlex crystal, scratch-free
• Bezel: Unidirectional rotating bezel with black and gold-tone insert
• Caseback: Exhibition caseback
• Bracelet: Original Seiko stainless steel bracelet
• Wrist size: Fits up to approx. 17.5 cm wrist circumference
• Box and papers: Not included
• Guarantee: 6-month functionality guarantee

Condition:
The watch is in excellent overall condition. The stainless steel case remains sharp and attractive, with a well-preserved combination of brushed and polished surfaces. Only very light signs of wear are visible, consistent with careful use. The black and gold-tone rotating bezel is in excellent condition and operates correctly.
The black dial is clean and very well preserved, with crisp printing, bright gold-tone accents and clean applied markers. The broad luminous hands and indices remain attractive, and the day-date display is clear and fully legible. The original curved Hardlex crystal is clear and scratch-free.
The watch is fitted with its original Seiko stainless steel bracelet, which is in very good condition with light surface marks from normal use. The Seiko 4R36 automatic movement is running well; part of the movement has been cleaned to support long-term reliable operation, and it is not currently in need of a full service. All functions operate correctly. The watch is sold without box and papers.

The watch has been partially cleaned by our professional watchmaker and tested for full functionality. The water resistance of the watch cannot be guaranteed.