Seiko Bell-Matic models share a core set of technical traits such as automatic mechanical movement with integrated mechanical alarm, materials, but dimensions and some details vary by reference. The specifications below describe the typical Bell-Matic 4006 series.
- Movement
- Automatic mechanical with alarm, Seiko 4006/4006A, 17–27 jewels, 19,800 bph.
- Caliber
- 4006 / 4006A
- Case size
- ~37.5–38 mm
- Case thickness
- Typically about 13–14 mm
- Case material
- Stainless steel
- Case shape
- Mostly round / slightly tonneau; special UFO/cushion variants exist.
- Complications
- Day-date, mechanical alarm with ~10–11 second ring
- Crystal
- Acrylic with tension ring
- Dial colour
- Multiple colors including white, black, bright blue, blue-gold, black-red
- Lug width
- Commonly 18–20 mm; some proprietary widths (e.g., 19.5 mm, 23 mm)
- Water resistance
- Not consistently specified; treat as minimal/unknown for vintage use.
- Release year
- 1966
