This is a gadget connected to the telephone. The unit has a Switch which when pressed disconnects the telephone line tempororily for 10 minutes & a led glows on the unit. After 10 minutes the led goes off & telephone is restored to normal working condition. During this 10 minutes if somebody dials the number he gets engage tone. This unit is useful during meetings or when you don't want to be disturbed. A Reset button is provided to reset the unit.