What is a double roller feature in a watch?

The double roller feature in a watch refers specifically to a mechanism that incorporates two rollers (also called "jewels") with one ruby pin. This design enhances the functionality and precision of the watch's movement, particularly in terms of regulating the escapement. The dual roller system ensures smoother operation, better durability, and reduces friction, thus providing better timekeeping accuracy. This feature is particularly common in high-quality watches where precision is paramount.

While water resistance, decorative elements, and winding mechanisms are important aspects of watches, they do not specifically relate to the function or definition of a double roller feature. Therefore, the focus on the two rollers and the ruby pin uniquely identifies the characteristic of the watch movement.