Seiko 6601, 6606, 6619,410, 2451, 790 Compatible Mainspring (Incarex)

These Seiko compatible mainsprings are NOS manufactured by Incarex, of France. Incarex had a good reputation for quality but is no longer in the consumer watch parts business. 

Amplitude Watch Parts ships from the USA, so there's no need to worry about long shipping delays or tariffs. 

Manufacturer: Incarex

Manufacturer Part Number: Seiko 401690

Compatible With: Seiko 6601A, 6601B, 6606A, 6619A,410, 2451, 790 

Type: Automatic with slipping bridle

Height: 1.35mm
Thickness: 0.10mm
Length: 360mm
Barrel Diameter: 9.0mm

Compatibility Notes: I used this mainspring for a Seiko 6619A. The arbor fit was perfect and after replacement the amplitude was measured at 260--Mike