Homer
Q Branch
Goldfinger
1964

As Q explained, the Homer was "...to be concealed in the car you're trailing while you keep out of site....audio-visual range -- 150 miles." The Homer's signals are picked up on a Receiver.

007 made quick use of this gadget by placing it in the trunk of Goldfinger's Rolls Royce Phantom 337 after their round of golf. This enabled him to trail Goldfinger to his metallurgy plant in Geneva, Switzerland, and ultimately find out the bigger scheme behind the gold smuggling.

Receiver
Q Branch
Goldfinger
1964

Concealed in the dashboard of the Aston Martin DB5, the Receiver picks up homing signals out to 150 miles. The transmitting device, called a Homer, is specifically designed to send signals to the Receiver.

The Receiver was put to use several times during the Goldfinger mission. It enabled 007 to track Goldfinger's Rolls Royce Phantom 337 to the airport and also to his Geneva headquarters. Felix Leiter had a Receiver installed in his Ford Mustang, which allowed him to track 007 to Kentucky. Later in the mission, Leiter tracked Mr. Solo, who unknowingly had Bond's Homer in his suit pocket.