The CX2.5/4/BU spring clamp series terminal blocks offer a time saving alternative to the popular screw clamp connection. The pre-stressed spring is opened using a tool (screw driver) so the conductor can be inserted into the insertion space through an opening in the spring leg. The conductor is pulled against the current bar under spring force when the tool is removed. A high contact force is achieved by the design of the spring clamp system. The design delivers a secure and reliable connection for any application.