What is a tool for measuring curved or irregular surfaces?

A tool commonly used for measuring curved or irregular surfaces is a contour gauge. This device features a series of thin, flexible pins that can conform to the shape of the surface, allowing for accurate replication of its contours. Once the desired shape is captured, the gauge can be transferred to a flat surface or used for further measurement and cutting. This makes it particularly useful in carpentry, Plumbing, and various crafting applications.