Tongue Interlock Safety Switch. IDEM IDIS-1 Compact Safety Interlock Switches are designed to provide position interlock detection for small moving guards.They are designed to fit to the leading edge of sliding, hinged or lift off machine guards.The rugged Stainless Steel actuator is designed to match a cam mechanism to provide a positively operated not easily defeatable interlock mechanism.The compact body, 22mm fixing profile and rotatable head..