A KG-300K-7 switching probe: a spring-loaded contact that also acts as a mechanical switch. As the fixture closes and the plunger is pushed back, an internal contact changes state at a defined point in the travel, so the tester can confirm that a board — or a connector, heatsink or component on it — is present and correctly seated before the test sequence runs.
Switching probes are what let a fixture fail fast and safely: a missing or misloaded board is caught by the presence check rather than by a wall of open-circuit failures, and power can be gated on the switch so nothing is energised until the DUT is seated. This part is the probe body itself; the matching socket, terminal and solder tab are stocked separately under the same KG-300K-7 designation.
Switching (presence-check) probe
Spring-loaded plunger with an internal switching contact
Supplied as the probe only; socket, terminal and solder tab are ordered separately
