The operator can add or subtract components depending upon the application. However, the resulting gaging system is not just a jumble of parts. Rather, all components appear to interlock neatly like jigsaw pieces, and are held in place by screws. Once the piece to be measured is set in place, the elements swing smoothly in for dimensioning. How you wish to view the measurement data is up to you.
Most systems accept dial gages, electronic column displays, and amplifiers.
Caliper-like systems display measurements on a digital readout. Modular, multidimensional gages, such as this system from Kurt Manufacturing, are typically composed of a base with a part support and various gaging elements, which are arranged by the operator to fit the piece being measured. Another advantage inherent in gage modularity is that, should you decide you'd like to measure a part with different dimensions, you need only reposition the gaging components. If the new part's dimensions are drastically different from the previous part's, or if you need to measure different types of dimensions, you can buy new components to adapt the gage to that application. The result, price-wise, is in your favor.