A project that will help you control the use of your telephone and keep your bill low. It can be connected on the phone line and disable the dialing beyond the 8th digit. Thus it is impossible for anyone to make a long-distance call unless you allow it. It can also disable dialing from the 5th digit so it is impossible to make anything but operator calls. It draws power from the telephone line. Very useful for public telephones, in businesses, shops, etc.