Plug this easy-to-use trailer light tester into the 4-flat connector of your tow vehicle and the LEDs light up to confirm the wiring connections. Test your right, left, tail and brake light wiring all with one handy light tester.

• Fits four-way flat plugs
• Male and female brass connectors
• Tests right, left, tail, and brake light wiring
• Small size fits easily in glove compartment or pocket