The Swan Neck Regulator is a precision adjustment mechanism used in watchmaking to fine-tune the rate of a watch's movement. It is named for its distinctive shape, which resembles the graceful curve of a swan's neck. This component is typically found in high-end mechanical watches and is part of the balance cock, which holds the balance wheel in place. The Swan Neck Regulator allows for minute adjustments to the tension of the hairspring, thereby regulating the speed at which the balance wheel oscillates. This precise control is crucial for ensuring the accuracy of the watch's timekeeping.

The mechanism consists of a fine screw and a curved spring, which work together to adjust the position of the regulator index. By turning the screw, watchmakers can move the regulator index slightly, altering the effective length of the hairspring. This adjustment changes the rate at which the balance wheel swings back and forth, allowing for precise calibration of the watch's timing. The Swan Neck Regulator is valued for its ability to provide stable and reliable adjustments, contributing to the overall precision and performance of the timepiece. Its presence is often a hallmark of superior craftsmanship and attention to detail in watchmaking.