OmegaNivaflex automatic mainsprings for wristwatchesNivaflex mainsprings from Boley for automatic winders. Products namewidthØthicknesscalibreitem No.2371x0.956.50.07OMEGA 670, 671, 680 - 682820237102373x0.956.50.081OMEGA 683, 684, 685820237302378x0.9511.50.12OMEGA 10109650101012082379x0.9511.50.15OMEGA 1000965010001208550x1,0110.00.11OMEGA 550 - 552, 751, 752965055012081040x1.0512.00.13OMEGA 1040, LEM 1345965010401208330x1.109.00.095OMEGA 330, 341820260502944x1,2012.00.106OMEGA 1045, LEM. 5100965010451208