The Seiko SPB505 Prospex Alpinist is the most versatile automatic watch in the legendary Alpinist lineup — now available at Lexor Miami, your authorized Seiko dealer in the USA.

Introduced in 2025 as part of the 8th-generation Alpinist refresh, the SPB505 features a striking black dial with a subtle warm brown undertone — a modern yet timeless aesthetic that transitions seamlessly from outdoor adventure to professional settings. Industry analysts have called it "the most commercially viable" of the three new Alpinist references, and it's easy to see why: the clean, all-black palette pairs with any outfit, any occasion, any lifestyle.

Under the hood, the SPB505 runs Seiko's upgraded Cal. 6R55 automatic movement with a 72-hour power reserve — enough to last through a full weekend without wearing it. The stainless steel case measures a highly wearable 39.5mm in diameter and just 12.7mm thin, protected by Seiko's new Diashield super-hard coating for exceptional scratch resistance. A sapphire crystal with magnifier and anti-reflective coating guarantees perfect legibility, while 200 meters of water resistance and a screw-down crown make this a serious tool watch at every price point.

The iconic rotating inner compass bezel — operated via the crown at 4 o'clock — connects the SPB505 to the Alpinist's mountaineering heritage since 1959. The transparent exhibition caseback reveals the 24-jewel movement through the engraved Alpinist mountain emblem.

Every Seiko SPB505 purchased at Lexor Miami includes the official 3-year Seiko manufacturer warranty, original box and papers, and free insured shipping across the USA. With over 3,100 five-star Google reviews and 20+ years as an authorized watch dealer, Lexor Miami is the most trusted source for authentic Seiko watches in Miami and nationwide.

Key features

• 8th-generation Seiko Prospex Alpinist — 30-year anniversary model (2025) — "Summit Black"
• Black dial with warm brown undertone — white LumiBrite hands and indices for maximum legibility
• Automatic movement Cal. 6R55 — 72-hour power reserve with manual winding capability
• Diashield scratch-resistant coating — new ultra-hard ceramic PVD on stainless steel case
• Sapphire crystal with magnifier — anti-reflective coating on inner surface
• Inner rotating compass bezel — operated via crown at 4 o'clock for field navigation
• 200M water resistance — screw-down crown, serious water activity ready
• Steel bracelet — 39.5mm case, 12.7mm thin, 46.4mm lug-to-lug, 20mm lug width
• Transparent exhibition caseback — engraved with the Alpinist mountain emblem
• Official 3-year Seiko manufacturer warranty — authorized US dealer purchase
• Free insured shipping — ships from Miami, FL across the entire USA 

Specifications 

Brand: Seiko
Collection: Seiko Luxe Prospex Alpinist
Model reference: SPB505J1
Nickname: Summit Black
Case diameter: 39.5 mm
Case thickness: 12.7 mm
Lug-to-lug: 46.4 mm
Lug width: 20 mm
Case material: Stainless steel with Diashield super-hard coating
Crystal: Sapphire with magnifier and anti-reflective coating (inner)
Dial color: Black with warm brown undertone, white details
Luminescence: LumiBrite on hands and indices
Movement: Caliber 6R55 — automatic with manual winding
Jewels: 24
Power reserve: Approx. 72 hours (3 days)
Frequency: 21,600 vph (3 Hz)
Accuracy: +25 to -15 seconds per day
Functions: Hours, minutes, seconds, date, stop-second hand
Compass bezel: Inner rotating, crown-operated at 4 o'clock
Water resistance: 200 m (20 bar)
Magnetic resistance: 4,800 A/m
Bracelet: Stainless steel, three-fold clasp with push-button release
Watch weight: 147 g (bracelet model)
Caseback: Transparent screw caseback with mountain emblem engraving
Country of origin: Japan
Warranty: 3-year official Seiko manufacturer warranty

100% authentic. 3,100+ five-star reviews. Authorized Seiko.
Free insured shipping across the USA. In-store pickup available in Miami, FL.