This chapter addresses the dimensional synthesis of four-bar linkages to achieve motion through two finitely separated positions (2 FSP). It begins by classifying synthesis types—function, path, trajectory, and motion generation—before focusing on the motion generation case. Geometric principles, including rotation poles and mediatrices, are applied to identify the fixed and moving pivots required for the desired motion. Methods for specifying either moving or fixed pivots are described, giving the designer flexibility depending on the constraints of the application. Practical examples such as trapdoor mechanisms are used to illustrate the synthesis steps, supported by figures and coordinate data. Special attention is paid to potential design defects like circuit defect and transmission angle limitations. The chapter emphasizes the iterative and graphical nature of the synthesis process, often supported by software tools like GeoGebra. Overall, it equips readers with practical strategies for two-position kinematic design.