Silver Balance Spring for ETA2660 ETA2661 Watch Movement Replacement – High-Quality Component | Exact Fit | Precise Mechanical Performance

This silver balance spring is designed specifically for the ETA2660 and ETA2661 watch movements—a premium replacement part aimed at watchmakers and serious hobbyists seeking superior performance. The spring features a Breguet coil with optimized geometry and material composition, ensuring excellent frequency stability and robust temperature compensation across varying conditions.

Constructed from top-grade anti-magnetic nickel-phosphorus alloy, this component offers exceptional long-term durability. Its thin profile guarantees minimal impact on drive power while maintaining precise isochronism. Befitting its quality, it meets military standards for shock resistance, making it well-suited for high-torque applications without sacrificing rate accuracy.