The balance wheel's pivots — the tiny steel pins at each end of its axle — are among the most delicate components in a mechanical watch. They are extremely thin by necessity (thinner pivots mean less friction) and rotate at high speed inside jewel bearings. A sharp impact, such as a dropped watch hitting a hard floor, can easily shear or bend these pivots, causing the movement to stop and requiring skilled repair.

Shock absorber systems address this vulnerability by mounting the balance wheel's jewel bearings in spring-loaded settings rather than fixing them rigidly in the movement plate. When an impact occurs, the spring yields slightly, absorbing the shock energy and allowing the pivot to deflect without breaking. Once the impact passes, the spring returns the bearing to its precise working position.

The two most widely used systems are Incabloc, developed in Switzerland in 1933, and KIF (Kif Flector), introduced in 1944, also Swiss. Both use a characteristic lyre-shaped spring to retain the bearing jewel, and both are highly effective — the vast majority of Swiss mechanical watches made since the mid-20th century use one or the other. Some manufacturers develop proprietary systems: Rolex uses its own Parachrom and Kif-based system; Omega developed the co-axial escapement geometry partly with shock resistance in mind. The presence of a shock absorber is now so standard that its absence is the exception rather than the rule.