Shown here are the common modular configurations and how the products can be “dovetailed” together to form larger terminal blocks with higher numbers of positions. Having this modular feature can be a real benefit for design engineers who are looking to order samples, or who want to have some flexibility in their prototyping with the number of circuits. It is also a benefit for companies who do not want to have to forecast, purchase, and stock a larger number of different position sizes. Simply having enough two, three, and four position blocks on hand may be able to satisfy a large number of different configurations. The dovetail features are designed such that centerline spacing is held within a given tolerance up to a certain number of position sizes. Understanding the manufacturers tolerances and recommended PCB hole dimensions is always a good idea.