17/21/27 jewels
The Seiko caliber 4006A is an in-house automatic movement with a mechanical alarm complication. It features a 10-second alarm function and incorporates Seiko's Magic Lever winding system with Diashock shock protection. The movement was produced in versions with 17, 21, or 27 jewels depending on the target market. It powered the Seiko Bell-Matic line of watches during the 1960s and 1970s before being discontinued.
TECHNICAL SPECIFICATIONS
Movement Type
Automatic
Jewel Count
17/21/27 jewels
Display Type
Analog
Winding
Automatic (Unidirectional)
Shock Protection
Diashock
COMPLICATIONS
Alarm
FEATURES
Magic Lever Winding
