There are various types of contact configurations for microswitches, and they can be selected according to different application requirements. Specifically, the contact configurations of microswitches include the following types:

1. Normally Open (NO) and Normally Closed (NC)
    Normally open (NO): The contact is open when no external force is applied. When an external force is applied, the contact is closed, making the circuit open.
    Normally closed (NC): When no external force is applied, the contact is closed. When an external force is applied, the contact is open, causing the circuit to break.

2. Single pole single pass (SPST)
    Single Pole Single Pass (SPST): This is the simplest contact configuration, with only one contact, and can be either normally open or normally closed.

3. single pole double pass (SPDT)
    Single Pole Double Pass (SPDT): This configuration contains a pole and a throw that can be switched between two circuits. It is equivalent to combining a normally open contact and a normally closed contact.

4. Double Pole Double Throw (DPDT)
    Double Pole Double Throw (DPDT): A contact configuration with two poles and two throws that allows for more complex circuit connections.

5. Special Customized Contact Configurations
    Special customized contact configurations: In order to meet the needs of a specific application, microswitches can also be specially customized according to the user's requirements.

In summary, microswitches are available in a wide variety of contact configurations, including normally open, normally closed, single-pole single-pass, single-pole double-pass, and double-knife double-throw. Each configuration has its own unique application scenarios and technical characteristics. Understanding these configuration types helps to properly select and apply microswitches to ensure circuit reliability and stability.