• 4-pin Small Size Trailer Light Tester & Circuit Troubleshooter for US,
  Plug tester into vehicles 4-pin connector and operate vehicle's turn
  signals, lights and brakes.
• When there is power present, the green light will glow.
• Fits 4-Pin Small Size Trailer Light Tester and Circuit Troubleshooter,
  Quickly and easily see if your trailer wiring is properly installed
  on your vehicle.
• No Batteries Required. LED light Indication.
• Test right, left, turn, and brake lights for proper function.
• Easy to carry, Compact Design Fits in your pocket.

• 4-pin Small Size Trailer Light Tester & Circuit Troubleshooter for US,
  Plug tester into vehicles 4-pin connector and operate vehicle's turn
  signals, lights and brakes.
• When there is power present, the green light will glow.
• Fits 4-Pin Small Size Trailer Light Tester and Circuit Troubleshooter,
  Quickly and easily see if your trailer wiring is properly installed
  on your vehicle.
• No Batteries Required. LED light Indication.
• Test right, left, turn, and brake lights for proper function.
• Easy to carry, Compact Design Fits in your pocket.