This is a gadget connected to the telephone. The unit has a switch which when pressed disconnects the telephone line temporority for 10 minutes & a led glows on the unit. After 10minutes 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. A additional circuit detects a special key code dialled by the caller when he gets engage tone. You can pass on the code to a person close to you. When the caller gets engage tone he is supposed to enter this code. When the code is entered telephone ringer rings momentorily & you can answer the phone. Thus that person can reach you even when you are busy.