ETANivaflex automatic mainsprings for wristwatchesNivaflex mainsprings from Boley for automatic winders. Products namewidthØthicknesscalibreitem No.2534x1.0510.50.115ETA 2890 - 2892-A2820253402539x1.067.00.72ETA 2000820253903132x1.2310.50.105ETA 2846820313203149x1.2310.50.132ETA 2821.2824820314903120x1.2512.00.10ETA 2820-22820312003193x1.306.50.075ETA 1216-1218820319303190x1.307.00.07ETA 2650-58820319003315x1.3010.50.12ETA 2870.2872820331503197x1.327.00.085ETA 2670. 2671820319704006x1.4511.00.125ETA 2770.2772820400604160x1.512.50.11ETA 775082041600