San Martin · Factory brand · China

San Martin SN021 B1 37mm (PT5000)

Ref. SN021-G-B1 · Explorer

Design reference: Rolex Explorer

San Martin SN021-G-B1 with Tiffany blue 3-6-9 dial and hexagon logo on steel bracelet
Photo: San Martin
  • San Martin SN021-G-B1 with black 3-6-9 dial, applied markers and hexagon logo
  • San Martin SN021-G-B2 with black dial, baton and dot markers and snowflake hands
  • San Martin SN021-G-B2 with Tiffany blue dial and snowflake hands
From $326
  • PT5000
  • 37 mm × 11.3 mm
  • Sapphire crystal
  • 100 m water resistance

Movement

Caliber
PT5000
Type
Automatic
Tier
Mid
Complications
Hours, Minutes, Seconds
Frequency
28,800 bph
Power reserve
38 h
Hacking
Yes
Accuracy (factory)
-12 / +12 s/day

Case

Diameter
37 mm
Lug to lug
45.5 mm
Thickness
11.3 mm
Lug width
20 mm
Material
Steel (316L)
Hardening
—
Water resistance
100 m
Crown
Screw-down
Case back
Solid, screw-down
Bezel
Fixed

Crystal & dial

Crystal
Sapphire
Shape
Box
Anti-reflective
Yes (side not stated)
Lume
BGW-9 blue on hands and markers

Bracelet & clasp

Style
Oyster
Links per row
3
Solid end links
—
Solid links
Yes
Link attachment
—
Taper
20 → 16 mm
Quick release
—
Half links
—
Clasp
Fold-over
Micro-adjust
Tool (pin holes), 4 positions
Diver extension
—

Weight

Head only
—
On bracelet
—
On strap
—
Stated weight (basis not given)
125 g

Prices

VariantConfigurationTypePriceUSDAs ofSource
B1 black dial—Street326 USD$3262026-10-24link
B1 Tiffany blue dial—Street326 USD$3262026-10-24link
B2 black dial, snowflake hands—Street326 USD$3262026-10-24link
B2 Tiffany blue dial, snowflake hands—Street326 USD$3262026-10-24link

Variants

NameReferenceDial
B1 black dialSN021-G-B1black
B1 Tiffany blue dialSN021-G-B1Tiffany blue
B2 black dial, snowflake handsSN021-G-B2black
B2 Tiffany blue dial, snowflake handsSN021-G-B2Tiffany blue

About this entry

84% of key specs known. Missing: hardening, end links, link attachment.

The SN021-G-B1 and SN021-G-B2 listings (written "SN0021-G-B1" and "SN0021-G-B2" in their spec lists) quote the same case and sell it with a PT5000 at $326 or a Sellita SW200 at $456, in black or Tiffany blue, with or without logo at the same price. This file is the PT5000 version of both; see sn021-b1-sw200 for the Sellita SW200. B1 has a 3-6-9 dial with "classic" hands; B2 has snowflake hands, and although its spec text repeats "369 Dial", its photos show baton and dot markers without numerals. Brand specs: 316L, 37mm (36mm bezel), 45.5mm lug-to-lug, 11.3mm (not stated whether that includes the crystal), 20mm lugs, top-hat sapphire with AR coating (side not stated), polished steel bezel (recorded as fixed with no insert), 3D hour markers, BGW-9 blue lume on hands and markers, screw-down crown with hexagon logo, brushed screw-down caseback, solid 316L bracelet 20mm tapering to 16mm, folding clasp with safety and 4 micro-adjust holes (recorded as tool micro-adjust; the B1 listing says the clasp has since changed to a thinner one), 100m, about 125g (not stated what was weighed). Bracelet style is from photos. Kept apart from the original SN021-G (sn021-pt5000: sapphire not called top-hat, 11mm, 45mm lug-to-lug, 133g) and from the SN021-G-B3 (sn021-b3-pt5000), whose listing quotes 45.9mm lug-to-lug for the B2's snowflake-hand design; if a review shows these are one case, merge them. Inspired_by is read from the design (B1's 3-6-9 dial on a 36mm-class explorer case) and the listing titles' "explorer"; the brand does not name the Rolex. The B2 variants' snowflake hands and baton markers follow the Tudor Black Bay 36 instead (see sn021-b3-pt5000). The movement has a date but the photos show no date window, so complications are time only. Every variation showed "Out of stock" on 2026-10-24, so production status is unknown.

Last verified: 2026-10-24. Edit or correct this entry.

Sources