When LED's are installed they do not draw the same amount of current as the halogen bulb they replaced and some cars will indicate the bulb is burnt out. Installing the resistor can mimic the current draw of the halogen bulb so the car doesn't give a bulb failure message.

Resistors are sold individually and if being used on turn signals you will need 1 resistor for each LED bulb.

Resistors are non-refundable.