Rotary Phones allowed the customer to place a telephone call without the individual help of an operator. On the rotary phone dial, the numbers are arranged in a circular layout so that a phone dial may be rotated with one finger from the position of each number to a fixed finger stop position, which is a mechanical barrier to prevent further rotation. When released at the finger stop, the wheel returns to its home position. During this return rotation, the dial interrupts the direct electrical current of the telephone line a specific number of times for each number, and thereby generates electrical pulses which the telephone exchange decodes. Each of the ten numbers is encoded in sequences of up to ten pulses for a 0.