![Jaeger LeCoultre® calibre # 840 balance cock screw](http://perrinwatchparts.com/cdn/shop/products/LC-8405121_600x600.png?v=1697246757)
Jaeger LeCoultre® balance cock screw, part # 5121, calibre # 840
balance cock screw to fit Jaeger LeCoultre® calibres: 840
* H. & W. Perrin Company Limited is independent of and not affiliated with or sponsored by Jaeger LeCoultre®. Jaeger LeCoultre® warranty does not apply to parts supplied by H. & W. Perrin Company Limited. Using generic parts may devalue your watch.