Seiko Prospex - "Marine Master" 300M Black DialSLA021J1
A bezel designed for a purpose
The professional level of the specifications becomes clear when you study the precise and secure operation of the uni-directional bezel. It's 120 ratchet design delivers more precise use and greater safety and the deep grooves make its operation easier and more secure, even at depth.
Highly durable zirconia ceramic bezel
The Zirconia ceramic will last a lifetime and longer, protecting the watch from rust and scratches so that the beauty of its deep black color endures for years to come.
A special long-lasting LumiBrite coating on the hands ensures legibility at greater depths for longer than ever before. The 5, 10, 15, and 20 minute markers on the uni-directional rotating bezel are also coated in this new LumiBrite, adding extra security for divers.
Movement: Caliber 8L35
This edition is equipped with the high-grade caliber 8L35, which is hand assembled and adjusted by Seiko's master watchmakers at the Shizukuishi Watch Studio in Morioka. Assembled from 192 parts, it beats at 28,000 vibrations per hour and has a power reserve of 50 hours.
An extra strap
A second attachment is also offered. This is a strap, made from high-strength silicone which is extremely resistant to sea water and perspiration sweat as well as being perfect for diving use with its accordion-style structure which allows it to expand and contract as the underwater pressure changes.
- Driving system: Automatic
- Vibrations: 28,800 vibrations per hour (8 beats per second)
- Power reserve: 50 hours
- Number of jewels: 26
- Stainless steel case and bracelet with super-hard coating
- Sapphire crystal with anti-reflective coating
- Zirconia ceramic bezel
- Screw-down crown
- Water resistance: 300m saturation diver’s
- Magnetic resistance: 16,000 A/m
- Diameter: 44.3 mm, Thickness: 15.4 mm
- Stainless steel bracelet with three-fold clasp with push button release, secure lock and slide adjuster
Also Known As SBDX023