Sinn SZ03

	Brand:	Sinn
	Family:	Sinn SZ
	Height:
	Jewels:	26
	Reserve:	hours
	Frequency:	28,800 A/h
	Winding:	Automatic, Bi-Directional Automatic Winding, Central Rotor Automatic Winding
	Diameter:	30.00 mm
	Complications:	2-Button, Cam Switching Chronograph, Chronograph, Date, Date by Pointer, Day, Month, Week Number
	Hands:	60 Minute Chronograph Hand at 12:00, Central 60 Second Chronograph Hand, Central Date Pointer, Central Hour Hand, Central Minute Hand, Day Window at 11:30, Month Window at 12:30, Small Seconds Hand at 9:00, Week Number Hand at 6:00

Distinguishing Technical Characteristics
Central-Rotor Automatic Clockwise Balance Cock Balance at 1:30 Central Rotor
Production: 2014 – Current
1910s	1920s	1930s	1940s	1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s

Sinn’s Cal. SZ03 is an automatic chronograph movement based on the ETA 7750.

Sinn has long used the ETA/Valjoux 7750 movement for their chronograph watches, but began reworking the movement in the 2003 as the SZ01. This was followed in 2014 by this Cal. SZ03. In addition to a 60 minute (rather than 30 minute) chronograph counter at 12:00, as in Cal. SZ02, Cal. SZ03 features an unusual calendar arrangement: Windows at 12:00 show the day of week and month, a central pointer shows the date, and the subdial at 6:00 shows the week number.

This movement was used in the Sinn 6052 Frankfurt Financial District Watch with calendar week display.

Sinn SZ01 Family of Movements

Sinn began working on their in-house modifications on the Valjoux 7750 base in 2003, introducing their Cal. SZ01 in the 2006 World Cup Football timer and EZM 1.1. These included a central chronograph minutes hand like the famous Lemania 5100. This was quickly followed by the Cal. SZ02, which moved the chronograph minutes to a subdial at 12. Cal. SZ03 (2014) and Cal. SZ06 (2019) add a week number counter or moon phase as well as a day and month window, while Cal. SZ05 (2011) moves the chronograph 60 minute subdial to 3. As of 2025, Sinn is phasing out their SZ series in favor of similar movements (Cal. SW515 and Cal. SW535) produced by Sellita.